{"id":2142,"date":"2013-05-08T01:34:28","date_gmt":"2013-05-08T09:34:28","guid":{"rendered":"http:\/\/www.mysqltutorial.org\/?page_id=2142"},"modified":"2024-01-29T21:13:18","modified_gmt":"2024-01-30T04:13:18","slug":"mysql-update-join","status":"publish","type":"page","link":"https:\/\/www.mysqltutorial.org\/mysql-basics\/mysql-update-join\/","title":{"rendered":"MySQL UPDATE JOIN"},"content":{"rendered":"\n<p><strong>Summary<\/strong>: in this tutorial, you will learn how to use the <strong>MySQL UPDATE JOIN<\/strong> statement to perform the cross-table update.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Introduction to MySQL UPDATE JOIN statement<\/h2>\n\n\n\n<p>You often use <a href=\"https:\/\/www.mysqltutorial.org\/mysql-basics\/mysql-join\/\">joins<\/a> to query rows from a table that have (in the case of <code><a href=\"https:\/\/www.mysqltutorial.org\/mysql-basics\/mysql-inner-join\/\">INNER JOIN<\/a><\/code>) or may not have (in the case of <code><a href=\"https:\/\/www.mysqltutorial.org\/mysql-basics\/mysql-left-join\/\">LEFT JOIN<\/a><\/code>) matching rows in another table. <\/p>\n\n\n\n<p>In MySQL, you can also use the <code>JOIN<\/code> clauses in the <a href=\"https:\/\/www.mysqltutorial.org\/mysql-basics\/mysql-update\/\"><code>UPDATE<\/code><\/a> statement to update rows in one table based on values from another table. The <code>UPDATE JOIN<\/code> statement is useful when you need to modify data across related tables.<\/p>\n\n\n\n<p>The syntax of the MySQL <code>UPDATE JOIN<\/code> &nbsp;is as follows:<\/p>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-1\" data-shcb-language-name=\"SQL (Structured Query Language)\" data-shcb-language-slug=\"sql\"><span><code class=\"hljs language-sql\"><span class=\"hljs-keyword\">UPDATE<\/span> T1\n&#91;<span class=\"hljs-keyword\">INNER<\/span> <span class=\"hljs-keyword\">JOIN<\/span> | <span class=\"hljs-keyword\">LEFT<\/span> <span class=\"hljs-keyword\">JOIN<\/span>] T2 <span class=\"hljs-keyword\">ON<\/span> T1.C1 = T2.C1\n<span class=\"hljs-keyword\">SET<\/span> T1.C2 = T2.C2, \n    T2.C3 = expr\n<span class=\"hljs-keyword\">WHERE<\/span> condition;<\/code><\/span><small class=\"shcb-language\" id=\"shcb-language-1\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">SQL (Structured Query Language)<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">sql<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<p>How it works:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>First, specify the table that you want to update after the UPDATE keyword (<code>T1<\/code>).<\/li>\n\n\n\n<li>Second, use either <code>INNER JOIN<\/code> &nbsp;or <code>LEFT JOIN<\/code> &nbsp;and a join predicate. The <code>JOIN<\/code> clause must appear right after the <code>UPDATE<\/code> clause.<\/li>\n\n\n\n<li>Third, assign new values to the columns of the <code>T1<\/code> table that you want to update data.<\/li>\n\n\n\n<li>Finally, specify a condition in the <code><a href=\"https:\/\/www.mysqltutorial.org\/mysql-basics\/mysql-where\/\">WHERE<\/a><\/code> clause to filter the rows for updating.<\/li>\n<\/ul>\n\n\n\n<p>If you follow the <code><a href=\"https:\/\/www.mysqltutorial.org\/mysql-basics\/mysql-update\/\">UPDATE<\/a><\/code> statement tutorial, you will notice that there is another way to update the data across tables using the following syntax:<\/p>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-2\" data-shcb-language-name=\"SQL (Structured Query Language)\" data-shcb-language-slug=\"sql\"><span><code class=\"hljs language-sql\"><span class=\"hljs-keyword\">UPDATE<\/span> T1\n<span class=\"hljs-keyword\">SET<\/span> T1.c2 = T2.c2,\n    T2.c3 = expr\n<span class=\"hljs-keyword\">WHERE<\/span> T1.c1 = T2.c1 <span class=\"hljs-keyword\">AND<\/span> condition;<\/code><\/span><small class=\"shcb-language\" id=\"shcb-language-2\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">SQL (Structured Query Language)<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">sql<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<p>This <code>UPDATE<\/code> statement works the same as&nbsp;<code>UPDATE JOIN<\/code> &nbsp;with&nbsp;an&nbsp;implicit <code>INNER JOIN<\/code> &nbsp;clause.&nbsp;It means you can rewrite the above statement as follows:<\/p>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-3\" data-shcb-language-name=\"SQL (Structured Query Language)\" data-shcb-language-slug=\"sql\"><span><code class=\"hljs language-sql\"><span class=\"hljs-keyword\">UPDATE<\/span> T1\n<span class=\"hljs-keyword\">INNER<\/span> <span class=\"hljs-keyword\">JOIN<\/span> T2 <span class=\"hljs-keyword\">ON<\/span> T1.C1 = T2.C1\n<span class=\"hljs-keyword\">SET<\/span> T1.C2 = T2.C2,\n      T2.C3 = expr\n<span class=\"hljs-keyword\">WHERE<\/span> condition;<\/code><\/span><small class=\"shcb-language\" id=\"shcb-language-3\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">SQL (Structured Query Language)<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">sql<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<h2 class=\"wp-block-heading\">MySQL UPDATE JOIN examples<\/h2>\n\n\n\n<p>Let&#8217;s explore some examples of using the <code>UPDATE JOIN<\/code> &nbsp;statement to have a better understanding.<\/p>\n\n\n\n<p>We&#8217;ll create a new database called <code>hr<\/code> that consists of two tables:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>The&nbsp; <code>employees<\/code> table stores employee data with employee id, name, performance, and salary.<\/li>\n\n\n\n<li>The <code>merits<\/code> table stores employee performance and merit percentage.<\/li>\n<\/ul>\n\n\n\n<p>The following statements create and load data in the <code>hr<\/code> sample database:<\/p>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-4\" data-shcb-language-name=\"SQL (Structured Query Language)\" data-shcb-language-slug=\"sql\"><span><code class=\"hljs language-sql\"><span class=\"hljs-keyword\">CREATE<\/span> <span class=\"hljs-keyword\">DATABASE<\/span> <span class=\"hljs-keyword\">IF<\/span> <span class=\"hljs-keyword\">NOT<\/span> <span class=\"hljs-keyword\">EXISTS<\/span> hr;\n\n<span class=\"hljs-keyword\">USE<\/span> hr;\n\n<span class=\"hljs-keyword\">CREATE<\/span> <span class=\"hljs-keyword\">TABLE<\/span> merits (\n  <span class=\"hljs-keyword\">performance<\/span> <span class=\"hljs-built_in\">INT<\/span> PRIMARY <span class=\"hljs-keyword\">KEY<\/span>, \n  percentage <span class=\"hljs-built_in\">DEC<\/span>(<span class=\"hljs-number\">11<\/span>, <span class=\"hljs-number\">2<\/span>) <span class=\"hljs-keyword\">NOT<\/span> <span class=\"hljs-literal\">NULL<\/span>\n);\n\n<span class=\"hljs-keyword\">CREATE<\/span> <span class=\"hljs-keyword\">TABLE<\/span> employees (\n  emp_id <span class=\"hljs-built_in\">INT<\/span> AUTO_INCREMENT PRIMARY <span class=\"hljs-keyword\">KEY<\/span>, \n  emp_name <span class=\"hljs-built_in\">VARCHAR<\/span>(<span class=\"hljs-number\">255<\/span>) <span class=\"hljs-keyword\">NOT<\/span> <span class=\"hljs-literal\">NULL<\/span>, \n  <span class=\"hljs-keyword\">performance<\/span> <span class=\"hljs-built_in\">INT<\/span> <span class=\"hljs-keyword\">DEFAULT<\/span> <span class=\"hljs-literal\">NULL<\/span>, \n  salary <span class=\"hljs-built_in\">DEC<\/span>(<span class=\"hljs-number\">11<\/span>, <span class=\"hljs-number\">2<\/span>) <span class=\"hljs-keyword\">DEFAULT<\/span> <span class=\"hljs-literal\">NULL<\/span>, \n  <span class=\"hljs-keyword\">FOREIGN<\/span> <span class=\"hljs-keyword\">KEY<\/span> (<span class=\"hljs-keyword\">performance<\/span>) <span class=\"hljs-keyword\">REFERENCES<\/span> merits (<span class=\"hljs-keyword\">performance<\/span>)\n);\n\n<span class=\"hljs-keyword\">INSERT<\/span> <span class=\"hljs-keyword\">INTO<\/span> merits(<span class=\"hljs-keyword\">performance<\/span>, percentage) \n<span class=\"hljs-keyword\">VALUES<\/span> \n  (<span class=\"hljs-number\">1<\/span>, <span class=\"hljs-number\">0<\/span>), \n  (<span class=\"hljs-number\">2<\/span>, <span class=\"hljs-number\">0.01<\/span>), \n  (<span class=\"hljs-number\">3<\/span>, <span class=\"hljs-number\">0.03<\/span>), \n  (<span class=\"hljs-number\">4<\/span>, <span class=\"hljs-number\">0.05<\/span>), \n  (<span class=\"hljs-number\">5<\/span>, <span class=\"hljs-number\">0.08<\/span>);\n\n<span class=\"hljs-keyword\">INSERT<\/span> <span class=\"hljs-keyword\">INTO<\/span> employees(emp_name, <span class=\"hljs-keyword\">performance<\/span>, salary) \n<span class=\"hljs-keyword\">VALUES<\/span> \n  (<span class=\"hljs-string\">'Mary Doe'<\/span>, <span class=\"hljs-number\">1<\/span>, <span class=\"hljs-number\">50000<\/span>), \n  (<span class=\"hljs-string\">'Cindy Smith'<\/span>, <span class=\"hljs-number\">3<\/span>, <span class=\"hljs-number\">65000<\/span>), \n  (<span class=\"hljs-string\">'Sue Greenspan'<\/span>, <span class=\"hljs-number\">4<\/span>, <span class=\"hljs-number\">75000<\/span>), \n  (<span class=\"hljs-string\">'Grace Dell'<\/span>, <span class=\"hljs-number\">5<\/span>, <span class=\"hljs-number\">125000<\/span>), \n  (<span class=\"hljs-string\">'Nancy Johnson'<\/span>, <span class=\"hljs-number\">3<\/span>, <span class=\"hljs-number\">85000<\/span>), \n  (<span class=\"hljs-string\">'John Doe'<\/span>, <span class=\"hljs-number\">2<\/span>, <span class=\"hljs-number\">45000<\/span>), \n  (<span class=\"hljs-string\">'Lily Bush'<\/span>, <span class=\"hljs-number\">3<\/span>, <span class=\"hljs-number\">55000<\/span>);<\/code><\/span><small class=\"shcb-language\" id=\"shcb-language-4\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">SQL (Structured Query Language)<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">sql<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<h3 class=\"wp-block-heading\">MySQL UPDATE JOIN example with INNER JOIN clause<\/h3>\n\n\n\n<p>Suppose you want to increment each employee&#8217;s salary by a percentage based on their performance.<\/p>\n\n\n\n<p>The following statement updates the <code>salary<\/code> column in the <code>employees<\/code> table by performing an <code>INNER JOIN<\/code> with the <code>merits<\/code> table based on matching values in the <code>performance<\/code> column:<\/p>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-5\" data-shcb-language-name=\"SQL (Structured Query Language)\" data-shcb-language-slug=\"sql\"><span><code class=\"hljs language-sql\"><span class=\"hljs-keyword\">UPDATE<\/span> \n  employees \n  <span class=\"hljs-keyword\">INNER<\/span> <span class=\"hljs-keyword\">JOIN<\/span> merits <span class=\"hljs-keyword\">ON<\/span> employees.performance = merits.performance \n<span class=\"hljs-keyword\">SET<\/span> \n  salary = salary + salary * percentage;<\/code><\/span><small class=\"shcb-language\" id=\"shcb-language-5\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">SQL (Structured Query Language)<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">sql<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<p>Output:<\/p>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-6\" data-shcb-language-name=\"CSS\" data-shcb-language-slug=\"css\"><span><code class=\"hljs language-css\"><span class=\"hljs-selector-tag\">Query<\/span> <span class=\"hljs-selector-tag\">OK<\/span>, 6 <span class=\"hljs-selector-tag\">rows<\/span> <span class=\"hljs-selector-tag\">affected<\/span> (0<span class=\"hljs-selector-class\">.01<\/span> <span class=\"hljs-selector-tag\">sec<\/span>)\n<span class=\"hljs-selector-tag\">Rows<\/span> <span class=\"hljs-selector-tag\">matched<\/span>: 7  <span class=\"hljs-selector-tag\">Changed<\/span>: 6  <span class=\"hljs-selector-tag\">Warnings<\/span>: 0<\/code><\/span><small class=\"shcb-language\" id=\"shcb-language-6\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">CSS<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">css<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<p>How the query works:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>UPDATE employees:<\/strong> Specifies that we want to update the <code>employees<\/code> table.<\/li>\n\n\n\n<li><strong>INNER JOIN merits ON employees.performance = merits.performance:<\/strong> Performs an INNER JOIN with the <code>merits<\/code> table based on the condition that the <code>performance<\/code> column values match between the <code>employees<\/code> and <code>merits<\/code> tables. This means only the rows with matching performance values in both tables will be considered for the update.<\/li>\n\n\n\n<li><strong>SET salary = salary + salary * percentage:<\/strong> Updates the <code>salary<\/code> column in the <code>employees<\/code> table. Each employee&#8217;s salary is updated based on the percentage: <code>salary + salary * percentage<\/code>.<\/li>\n<\/ul>\n\n\n\n<p>Because the <code>UPDATE<\/code> statement does not have the <code>WHERE<\/code> clause, it updates all rows <code>employees<\/code> table.<\/p>\n\n\n\n<p>The following statement retrieves data from the <code>employees<\/code> table to verify the updates:<\/p>\n\n\n<pre class=\"wp-block-code\"><span><code class=\"hljs\">SELECT * FROM employees;<\/code><\/span><\/pre>\n\n\n<p>Output:<\/p>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-7\" data-shcb-language-name=\"JavaScript\" data-shcb-language-slug=\"javascript\"><span><code class=\"hljs language-javascript\">+--------+---------------+-------------+--------+\n| emp_id | emp_name      | performance | salary |\n+--------+---------------+-------------+--------+\n|      <span class=\"hljs-number\">1<\/span> | Mary Doe      |           <span class=\"hljs-number\">1<\/span> |  <span class=\"hljs-number\">50000<\/span> |\n|      <span class=\"hljs-number\">2<\/span> | Cindy Smith   |           <span class=\"hljs-number\">3<\/span> |  <span class=\"hljs-number\">66950<\/span> |\n|      <span class=\"hljs-number\">3<\/span> | Sue Greenspan |           <span class=\"hljs-number\">4<\/span> |  <span class=\"hljs-number\">78750<\/span> |\n|      <span class=\"hljs-number\">4<\/span> | Grace Dell    |           <span class=\"hljs-number\">5<\/span> | <span class=\"hljs-number\">135000<\/span> |\n|      <span class=\"hljs-number\">5<\/span> | Nancy Johnson |           <span class=\"hljs-number\">3<\/span> |  <span class=\"hljs-number\">87550<\/span> |\n|      <span class=\"hljs-number\">6<\/span> | John Doe      |           <span class=\"hljs-number\">2<\/span> |  <span class=\"hljs-number\">45450<\/span> |\n|      <span class=\"hljs-number\">7<\/span> | Lily Bush     |           <span class=\"hljs-number\">3<\/span> |  <span class=\"hljs-number\">56650<\/span> |\n+--------+---------------+-------------+--------+\n<span class=\"hljs-number\">7<\/span> rows <span class=\"hljs-keyword\">in<\/span> <span class=\"hljs-keyword\">set<\/span> (0.00 sec)<\/code><\/span><small class=\"shcb-language\" id=\"shcb-language-7\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">JavaScript<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">javascript<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<h3 class=\"wp-block-heading\">MySQL UPDATE JOIN example with LEFT JOIN<\/h3>\n\n\n\n<p>Suppose the company has two new hires employees with the performances are NULL:<\/p>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-8\" data-shcb-language-name=\"SQL (Structured Query Language)\" data-shcb-language-slug=\"sql\"><span><code class=\"hljs language-sql\"><span class=\"hljs-keyword\">TRUNCATE<\/span> <span class=\"hljs-keyword\">TABLE<\/span> employees;\n\n<span class=\"hljs-keyword\">INSERT<\/span> <span class=\"hljs-keyword\">INTO<\/span> employees(emp_name, <span class=\"hljs-keyword\">performance<\/span>, salary) \n<span class=\"hljs-keyword\">VALUES<\/span> \n  (<span class=\"hljs-string\">'Mary Doe'<\/span>, <span class=\"hljs-number\">1<\/span>, <span class=\"hljs-number\">50000<\/span>), \n  (<span class=\"hljs-string\">'Cindy Smith'<\/span>, <span class=\"hljs-number\">3<\/span>, <span class=\"hljs-number\">65000<\/span>), \n  (<span class=\"hljs-string\">'Sue Greenspan'<\/span>, <span class=\"hljs-number\">4<\/span>, <span class=\"hljs-number\">75000<\/span>), \n  (<span class=\"hljs-string\">'Grace Dell'<\/span>, <span class=\"hljs-number\">5<\/span>, <span class=\"hljs-number\">125000<\/span>), \n  (<span class=\"hljs-string\">'Nancy Johnson'<\/span>, <span class=\"hljs-number\">3<\/span>, <span class=\"hljs-number\">85000<\/span>), \n  (<span class=\"hljs-string\">'John Doe'<\/span>, <span class=\"hljs-number\">2<\/span>, <span class=\"hljs-number\">45000<\/span>), \n  (<span class=\"hljs-string\">'Lily Bush'<\/span>, <span class=\"hljs-number\">3<\/span>, <span class=\"hljs-number\">55000<\/span>),\n  (<span class=\"hljs-string\">'Jack William'<\/span>, <span class=\"hljs-literal\">NULL<\/span>, <span class=\"hljs-number\">43000<\/span>), \n  (<span class=\"hljs-string\">'Ricky Bond'<\/span>, <span class=\"hljs-literal\">NULL<\/span>, <span class=\"hljs-number\">52000<\/span>);<\/code><\/span><small class=\"shcb-language\" id=\"shcb-language-8\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">SQL (Structured Query Language)<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">sql<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<p>Because these employees are new hires so their performance data is not available or <code>NULL<\/code>:<\/p>\n\n\n<pre class=\"wp-block-code\"><span><code class=\"hljs\">SELECT * FROM employees;<\/code><\/span><\/pre>\n\n\n<p>Output:<\/p>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-9\" data-shcb-language-name=\"PHP\" data-shcb-language-slug=\"php\"><span><code class=\"hljs language-php\">+--------+---------------+-------------+--------+\n| emp_id | emp_name      | performance | salary |\n+--------+---------------+-------------+--------+\n|      <span class=\"hljs-number\">1<\/span> | Mary Doe      |           <span class=\"hljs-number\">1<\/span> |  <span class=\"hljs-number\">50000<\/span> |\n|      <span class=\"hljs-number\">2<\/span> | Cindy Smith   |           <span class=\"hljs-number\">3<\/span> |  <span class=\"hljs-number\">66950<\/span> |\n|      <span class=\"hljs-number\">3<\/span> | Sue Greenspan |           <span class=\"hljs-number\">4<\/span> |  <span class=\"hljs-number\">78750<\/span> |\n|      <span class=\"hljs-number\">4<\/span> | Grace Dell    |           <span class=\"hljs-number\">5<\/span> | <span class=\"hljs-number\">135000<\/span> |\n|      <span class=\"hljs-number\">5<\/span> | Nancy Johnson |           <span class=\"hljs-number\">3<\/span> |  <span class=\"hljs-number\">87550<\/span> |\n|      <span class=\"hljs-number\">6<\/span> | John Doe      |           <span class=\"hljs-number\">2<\/span> |  <span class=\"hljs-number\">45450<\/span> |\n|      <span class=\"hljs-number\">7<\/span> | Lily Bush     |           <span class=\"hljs-number\">3<\/span> |  <span class=\"hljs-number\">56650<\/span> |\n|      <span class=\"hljs-number\">8<\/span> | Jack William  |        <span class=\"hljs-keyword\">NULL<\/span> |  <span class=\"hljs-number\">43000<\/span> |\n|      <span class=\"hljs-number\">9<\/span> | Ricky Bond    |        <span class=\"hljs-keyword\">NULL<\/span> |  <span class=\"hljs-number\">52000<\/span> |\n+--------+---------------+-------------+--------+\n<span class=\"hljs-number\">9<\/span> rows in set (<span class=\"hljs-number\">0.00<\/span> sec)<\/code><\/span><small class=\"shcb-language\" id=\"shcb-language-9\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">PHP<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">php<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<p>To raise the salary for all employees including new hires, you cannot use the <code>UPDATE INNER JOIN<\/code> statement because the performance scores of the new hires are not available in the <code>merits<\/code> table. This is where the <code>UPDATE LEFT JOIN<\/code> statement comes to the rescue.<\/p>\n\n\n\n<p>The <code>UPDATE LEFT JOIN<\/code> &nbsp;statement updates a row in a table when it does not have a corresponding row in another table.<\/p>\n\n\n\n<p>For example, you can increase the salary for a new hire by 1.5% and other employees based on their performances\u00a0using the following statement:<\/p>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-10\" data-shcb-language-name=\"SQL (Structured Query Language)\" data-shcb-language-slug=\"sql\"><span><code class=\"hljs language-sql\"><span class=\"hljs-keyword\">UPDATE<\/span> \n  employees \n  <span class=\"hljs-keyword\">LEFT<\/span> <span class=\"hljs-keyword\">JOIN<\/span> merits <span class=\"hljs-keyword\">ON<\/span> employees.performance = merits.performance \n<span class=\"hljs-keyword\">SET<\/span> \n  salary = salary + salary * <span class=\"hljs-keyword\">COALESCE<\/span>(percentage, <span class=\"hljs-number\">0.015<\/span>);<\/code><\/span><small class=\"shcb-language\" id=\"shcb-language-10\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">SQL (Structured Query Language)<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">sql<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<p>Output:<\/p>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-11\" data-shcb-language-name=\"CSS\" data-shcb-language-slug=\"css\"><span><code class=\"hljs language-css\"><span class=\"hljs-selector-tag\">Query<\/span> <span class=\"hljs-selector-tag\">OK<\/span>, 8 <span class=\"hljs-selector-tag\">rows<\/span> <span class=\"hljs-selector-tag\">affected<\/span> (0<span class=\"hljs-selector-class\">.01<\/span> <span class=\"hljs-selector-tag\">sec<\/span>)\r\n<span class=\"hljs-selector-tag\">Rows<\/span> <span class=\"hljs-selector-tag\">matched<\/span>: 9  <span class=\"hljs-selector-tag\">Changed<\/span>: 8  <span class=\"hljs-selector-tag\">Warnings<\/span>: 0<\/code><\/span><small class=\"shcb-language\" id=\"shcb-language-11\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">CSS<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">css<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<p>The salary of the employee (Mary Doe) who has a performance score of 1 was not updated. Therefore, we have 8 rows changed.<\/p>\n\n\n\n<p>The following statement retrieves the data from the <code>employees<\/code> table to verify the updates:<\/p>\n\n\n<pre class=\"wp-block-code\"><span><code class=\"hljs\">SELECT * FROM employees;<\/code><\/span><\/pre>\n\n\n<p>Output:<\/p>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-12\" data-shcb-language-name=\"PHP\" data-shcb-language-slug=\"php\"><span><code class=\"hljs language-php\">+--------+---------------+-------------+--------+\n| emp_id | emp_name      | performance | salary |\n+--------+---------------+-------------+--------+\n|      <span class=\"hljs-number\">1<\/span> | Mary Doe      |           <span class=\"hljs-number\">1<\/span> |  <span class=\"hljs-number\">50000<\/span> |\n|      <span class=\"hljs-number\">2<\/span> | Cindy Smith   |           <span class=\"hljs-number\">3<\/span> |  <span class=\"hljs-number\">66950<\/span> |\n|      <span class=\"hljs-number\">3<\/span> | Sue Greenspan |           <span class=\"hljs-number\">4<\/span> |  <span class=\"hljs-number\">78750<\/span> |\n|      <span class=\"hljs-number\">4<\/span> | Grace Dell    |           <span class=\"hljs-number\">5<\/span> | <span class=\"hljs-number\">135000<\/span> |\n|      <span class=\"hljs-number\">5<\/span> | Nancy Johnson |           <span class=\"hljs-number\">3<\/span> |  <span class=\"hljs-number\">87550<\/span> |\n|      <span class=\"hljs-number\">6<\/span> | John Doe      |           <span class=\"hljs-number\">2<\/span> |  <span class=\"hljs-number\">45450<\/span> |\n|      <span class=\"hljs-number\">7<\/span> | Lily Bush     |           <span class=\"hljs-number\">3<\/span> |  <span class=\"hljs-number\">56650<\/span> |\n|      <span class=\"hljs-number\">8<\/span> | Jack William  |        <span class=\"hljs-keyword\">NULL<\/span> |  <span class=\"hljs-number\">43645<\/span> |\n|      <span class=\"hljs-number\">9<\/span> | Ricky Bond    |        <span class=\"hljs-keyword\">NULL<\/span> |  <span class=\"hljs-number\">52780<\/span> |\n+--------+---------------+-------------+--------+\n<span class=\"hljs-number\">9<\/span> rows in set (<span class=\"hljs-number\">0.00<\/span> sec)<\/code><\/span><small class=\"shcb-language\" id=\"shcb-language-12\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">PHP<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">php<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<h2 class=\"wp-block-heading\">Summary<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Use the MySQL <code>UPDATE JOIN<\/code> &nbsp;with the <code>INNER JOIN<\/code> &nbsp;or <code>LEFT JOIN<\/code>&nbsp; clauses to perform cross-table updates.<\/li>\n<\/ul>\n<div class=\"helpful-block-content\" data-title=\"\">\n\t<header>\n\t\t<div class=\"wth-question\">Was this tutorial helpful? <\/div>\n\t\t<div class=\"wth-thumbs\">\n\t\t\t<button\n\t\t\t\tdata-post=\"2142\"\n\t\t\t\tdata-post-url=\"https:\/\/www.mysqltutorial.org\/mysql-basics\/mysql-update-join\/\"\n\t\t\t\tdata-post-title=\"MySQL UPDATE JOIN\"\n\t\t\t\tdata-response=\"1\"\n\t\t\t\tclass=\"wth-btn-rounded wth-yes-btn\"\n\t\t\t>\n\t\t\t\t<svg\n\t\t\t\t\txmlns=\"http:\/\/www.w3.org\/2000\/svg\"\n\t\t\t\t\tviewBox=\"0 0 24 24\"\n\t\t\t\t\tfill=\"none\"\n\t\t\t\t\tstroke=\"currentColor\"\n\t\t\t\t\tstroke-width=\"2\"\n\t\t\t\t\tstroke-linecap=\"round\"\n\t\t\t\t\tstroke-linejoin=\"round\"\n\t\t\t\t\tclass=\"feather feather-thumbs-up block w-full h-full\"\n\t\t\t\t>\n\t\t\t\t\t<path\n\t\t\t\t\t\td=\"M14 9V5a3 3 0 0 0-3-3l-4 9v11h11.28a2 2 0 0 0 2-1.7l1.38-9a2 2 0 0 0-2-2.3zM7 22H4a2 2 0 0 1-2-2v-7a2 2 0 0 1 2-2h3\"\n\t\t\t\t\t><\/path>\n\t\t\t\t<\/svg>\n\t\t\t\t<span class=\"sr-only\"> Yes <\/span>\n\t\t\t<\/button>\n\n\t\t\t<button\n\t\t\t\tdata-response=\"0\"\n\t\t\t\tdata-post=\"2142\"\n\t\t\t\tdata-post-url=\"https:\/\/www.mysqltutorial.org\/mysql-basics\/mysql-update-join\/\"\n\t\t\t\tdata-post-title=\"MySQL UPDATE JOIN\"\n\t\t\t\tclass=\"wth-btn-rounded wth-no-btn\"\n\t\t\t>\n\t\t\t\t<svg\n\t\t\t\t\txmlns=\"http:\/\/www.w3.org\/2000\/svg\"\n\t\t\t\t\tviewBox=\"0 0 24 24\"\n\t\t\t\t\tfill=\"none\"\n\t\t\t\t\tstroke=\"currentColor\"\n\t\t\t\t\tstroke-width=\"2\"\n\t\t\t\t\tstroke-linecap=\"round\"\n\t\t\t\t\tstroke-linejoin=\"round\"\n\t\t\t\t>\n\t\t\t\t\t<path\n\t\t\t\t\t\td=\"M10 15v4a3 3 0 0 0 3 3l4-9V2H5.72a2 2 0 0 0-2 1.7l-1.38 9a2 2 0 0 0 2 2.3zm7-13h2.67A2.31 2.31 0 0 1 22 4v7a2.31 2.31 0 0 1-2.33 2H17\"\n\t\t\t\t\t><\/path>\n\t\t\t\t<\/svg>\n\t\t\t\t<span class=\"sr-only\"> No <\/span>\n\t\t\t<\/button>\n\t\t<\/div>\n\t<\/header>\n\n\t<div class=\"wth-form hidden\">\n\t\t<div class=\"wth-form-wrapper\">\n\t\t\t<div class=\"wth-title\"><\/div>\n\t\t\t\n\t\t\t<textarea class=\"wth-message\"><\/textarea>\n\n\t\t\t<button class=\"btn btn-primary wth-btn-submit\">Send<\/button>\n\t\t\t<button class=\"btn wth-btn-cancel\">Cancel<\/button>\n\t\t\n\t\t<\/div>\n\t<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>This tutorial shows you how to perform cross-table updates by using the MySQL UPDATE JOIN statement with the INNER JOIN or LEFT JOIN clause.<\/p>\n","protected":false},"author":2,"featured_media":0,"parent":174,"menu_order":60,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-2142","page","type-page","status-publish","hentry"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v27.5 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>MySQL UPDATE JOIN | Cross-Table Update in MySQL<\/title>\n<meta name=\"description\" content=\"This tutorial shows you how to perform cross-table updates by using the MySQL UPDATE JOIN statement with the INNER JOIN or LEFT JOIN clause.\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.mysqltutorial.org\/mysql-basics\/mysql-update-join\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"MySQL UPDATE JOIN | Cross-Table Update in MySQL\" \/>\n<meta property=\"og:description\" content=\"This tutorial shows you how to perform cross-table updates by using the MySQL UPDATE JOIN statement with the INNER JOIN or LEFT JOIN clause.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/www.mysqltutorial.org\/mysql-basics\/mysql-update-join\/\" \/>\n<meta property=\"og:site_name\" content=\"MySQL Tutorial\" \/>\n<meta property=\"article:modified_time\" content=\"2024-01-30T04:13:18+00:00\" \/>\n<meta name=\"twitter:label1\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data1\" content=\"3 minutes\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\\\/\\\/schema.org\",\"@graph\":[{\"@type\":\"WebPage\",\"@id\":\"https:\\\/\\\/www.mysqltutorial.org\\\/mysql-basics\\\/mysql-update-join\\\/\",\"url\":\"https:\\\/\\\/www.mysqltutorial.org\\\/mysql-basics\\\/mysql-update-join\\\/\",\"name\":\"MySQL UPDATE JOIN | Cross-Table Update in MySQL\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/www.mysqltutorial.org\\\/#website\"},\"datePublished\":\"2013-05-08T09:34:28+00:00\",\"dateModified\":\"2024-01-30T04:13:18+00:00\",\"description\":\"This tutorial shows you how to perform cross-table updates by using the MySQL UPDATE JOIN statement with the INNER JOIN or LEFT JOIN clause.\",\"breadcrumb\":{\"@id\":\"https:\\\/\\\/www.mysqltutorial.org\\\/mysql-basics\\\/mysql-update-join\\\/#breadcrumb\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\\\/\\\/www.mysqltutorial.org\\\/mysql-basics\\\/mysql-update-join\\\/\"]}]},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\\\/\\\/www.mysqltutorial.org\\\/mysql-basics\\\/mysql-update-join\\\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\\\/\\\/www.mysqltutorial.org\\\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"MySQL Basics\",\"item\":\"https:\\\/\\\/www.mysqltutorial.org\\\/mysql-basics\\\/\"},{\"@type\":\"ListItem\",\"position\":3,\"name\":\"MySQL UPDATE JOIN\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\\\/\\\/www.mysqltutorial.org\\\/#website\",\"url\":\"https:\\\/\\\/www.mysqltutorial.org\\\/\",\"name\":\"MySQL Tutorial\",\"description\":\"A comprehensive MySQL Tutorial\",\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\\\/\\\/www.mysqltutorial.org\\\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"en-US\"}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"MySQL UPDATE JOIN | Cross-Table Update in MySQL","description":"This tutorial shows you how to perform cross-table updates by using the MySQL UPDATE JOIN statement with the INNER JOIN or LEFT JOIN clause.","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/www.mysqltutorial.org\/mysql-basics\/mysql-update-join\/","og_locale":"en_US","og_type":"article","og_title":"MySQL UPDATE JOIN | Cross-Table Update in MySQL","og_description":"This tutorial shows you how to perform cross-table updates by using the MySQL UPDATE JOIN statement with the INNER JOIN or LEFT JOIN clause.","og_url":"https:\/\/www.mysqltutorial.org\/mysql-basics\/mysql-update-join\/","og_site_name":"MySQL Tutorial","article_modified_time":"2024-01-30T04:13:18+00:00","twitter_misc":{"Est. reading time":"3 minutes"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"WebPage","@id":"https:\/\/www.mysqltutorial.org\/mysql-basics\/mysql-update-join\/","url":"https:\/\/www.mysqltutorial.org\/mysql-basics\/mysql-update-join\/","name":"MySQL UPDATE JOIN | Cross-Table Update in MySQL","isPartOf":{"@id":"https:\/\/www.mysqltutorial.org\/#website"},"datePublished":"2013-05-08T09:34:28+00:00","dateModified":"2024-01-30T04:13:18+00:00","description":"This tutorial shows you how to perform cross-table updates by using the MySQL UPDATE JOIN statement with the INNER JOIN or LEFT JOIN clause.","breadcrumb":{"@id":"https:\/\/www.mysqltutorial.org\/mysql-basics\/mysql-update-join\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/www.mysqltutorial.org\/mysql-basics\/mysql-update-join\/"]}]},{"@type":"BreadcrumbList","@id":"https:\/\/www.mysqltutorial.org\/mysql-basics\/mysql-update-join\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/www.mysqltutorial.org\/"},{"@type":"ListItem","position":2,"name":"MySQL Basics","item":"https:\/\/www.mysqltutorial.org\/mysql-basics\/"},{"@type":"ListItem","position":3,"name":"MySQL UPDATE JOIN"}]},{"@type":"WebSite","@id":"https:\/\/www.mysqltutorial.org\/#website","url":"https:\/\/www.mysqltutorial.org\/","name":"MySQL Tutorial","description":"A comprehensive MySQL Tutorial","potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/www.mysqltutorial.org\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"en-US"}]}},"_links":{"self":[{"href":"https:\/\/www.mysqltutorial.org\/wp-json\/wp\/v2\/pages\/2142","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.mysqltutorial.org\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.mysqltutorial.org\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.mysqltutorial.org\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.mysqltutorial.org\/wp-json\/wp\/v2\/comments?post=2142"}],"version-history":[{"count":5,"href":"https:\/\/www.mysqltutorial.org\/wp-json\/wp\/v2\/pages\/2142\/revisions"}],"predecessor-version":[{"id":14619,"href":"https:\/\/www.mysqltutorial.org\/wp-json\/wp\/v2\/pages\/2142\/revisions\/14619"}],"up":[{"embeddable":true,"href":"https:\/\/www.mysqltutorial.org\/wp-json\/wp\/v2\/pages\/174"}],"wp:attachment":[{"href":"https:\/\/www.mysqltutorial.org\/wp-json\/wp\/v2\/media?parent=2142"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}