{"id":2909,"date":"2019-08-12T00:50:41","date_gmt":"2019-08-12T07:50:41","guid":{"rendered":"https:\/\/oracletutorial.com\/?page_id=2909"},"modified":"2024-03-06T04:10:13","modified_gmt":"2024-03-06T11:10:13","slug":"oracle-row-level-triggers","status":"publish","type":"page","link":"https:\/\/www.oracletutorial.com\/plsql-tutorial\/oracle-row-level-triggers\/","title":{"rendered":"Oracle Row-level Triggers"},"content":{"rendered":"\n<p><strong>Summary<\/strong>: in this tutorial, you will learn about Oracle row-level triggers and how to use the <code>CREATE TRIGGER<\/code> statement to create a new row-level trigger.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id='introduction-to-oracle-row-level-triggers'>Introduction to Oracle row-level triggers <a href=\"#introduction-to-oracle-row-level-triggers\" class=\"anchor\" id=\"introduction-to-oracle-row-level-triggers\" title=\"Anchor for Introduction to Oracle row-level triggers\">#<\/a><\/h2>\n\n\n\n<p>Row-level triggers fires once for each row affected by the triggering event such as <code><a href=\"https:\/\/www.oracletutorial.com\/oracle-basics\/oracle-insert\/\">INSERT<\/a><\/code>, <code><a href=\"https:\/\/www.oracletutorial.com\/oracle-basics\/oracle-update\/\">UPDATE<\/a><\/code>, or <code><a href=\"https:\/\/www.oracletutorial.com\/oracle-basics\/oracle-delete\/\">DELETE<\/a><\/code>.<\/p>\n\n\n\n<p>Row-level triggers are useful for data-related activities such as data auditing and data validation.<\/p>\n\n\n\n<p>To create a new row-level trigger, you use the <code><a href=\"https:\/\/www.oracletutorial.com\/plsql-tutorial\/oracle-trigger\/\">CREATE TRIGGER<\/a><\/code> statement with the <code>FOR EACH ROW<\/code> clause.<\/p>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-1\" data-shcb-language-name=\"PostgreSQL SQL dialect and PL\/pgSQL\" data-shcb-language-slug=\"pgsql\"><span><code class=\"hljs language-pgsql\"><span class=\"hljs-keyword\">CREATE<\/span> <span class=\"hljs-keyword\">OR REPLACE<\/span> <span class=\"hljs-keyword\">TRIGGER<\/span> trigger_name\n    <span class=\"hljs-keyword\">BEFORE<\/span> | <span class=\"hljs-keyword\">AFTER<\/span>\n    <span class=\"hljs-keyword\">INSERT<\/span> <span class=\"hljs-keyword\">OR<\/span> <span class=\"hljs-keyword\">DELETE<\/span> <span class=\"hljs-keyword\">OR<\/span> <span class=\"hljs-keyword\">UPDATE<\/span> <span class=\"hljs-keyword\">OF<\/span> column1, column2, \u2026\n    <span class=\"hljs-keyword\">ON<\/span> <span class=\"hljs-built_in\">table_name<\/span>\n    <span class=\"hljs-keyword\">FOR<\/span> <span class=\"hljs-keyword\">EACH<\/span> <span class=\"hljs-keyword\">ROW<\/span>\n    <span class=\"hljs-keyword\">REFERENCING OLD<\/span> <span class=\"hljs-keyword\">AS<\/span> old_name\n    <span class=\"hljs-built_in\">NEW<\/span> <span class=\"hljs-keyword\">AS<\/span> new_name\n    <span class=\"hljs-keyword\">WHEN<\/span> (condition)\n<span class=\"hljs-keyword\">DECLARE<\/span>\n    \u2026\n<span class=\"hljs-keyword\">BEGIN<\/span>\n    \u2026\n<span class=\"hljs-keyword\">EXCEPTION<\/span>\n    \u2026\n<span class=\"hljs-keyword\">END<\/span>;\n<\/code><\/span><small class=\"shcb-language\" id=\"shcb-language-1\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">PostgreSQL SQL dialect and PL\/pgSQL<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">pgsql<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<p>The features which are applicable to the statement-level triggers are also available the row-level trigger:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Use <code><a href=\"https:\/\/www.oracletutorial.com\/plsql-tutorial\/oracle-raise_application_error\/\">raise_application_error()<\/a><\/code> to raise a user-defined exception<\/li>\n\n\n\n<li>Check if the current event is <code>INSERT<\/code>, <code>UPDATE<\/code>, and <code>DELETE<\/code> using the <code>INSERTING<\/code> or <code>DELETING<\/code> or <code>UPDATING<\/code>.<\/li>\n<\/ul>\n\n\n\n<p>On top of that, row-level triggers allow you to track the <code>BEFORE<\/code> and <code>AFTER<\/code> values.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id='the-old-new-column-values'>The :OLD &amp; :NEW column values <a href=\"#the-old-new-column-values\" class=\"anchor\" id=\"the-old-new-column-values\" title=\"Anchor for The &lt;code&gt;:OLD&lt;\/code&gt; &amp; &lt;code&gt;:NEW&lt;\/code&gt; column values\">#<\/a><\/h3>\n\n\n\n<p>Because row-level triggers execute within the context of a single row, you can access the old and new column values using the following syntax:<\/p>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-2\" data-shcb-language-name=\"PostgreSQL SQL dialect and PL\/pgSQL\" data-shcb-language-slug=\"pgsql\"><span><code class=\"hljs language-pgsql\">:<span class=\"hljs-built_in\">OLD<\/span>.<span class=\"hljs-built_in\">column_name<\/span>\n:<span class=\"hljs-built_in\">NEW<\/span>.<span class=\"hljs-built_in\">column_name<\/span>\n<\/code><\/span><small class=\"shcb-language\" id=\"shcb-language-2\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">PostgreSQL SQL dialect and PL\/pgSQL<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">pgsql<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<p>For example, this statement checks the value of the <code>credit_limit<\/code> column to see if the new credit is greater than the current credit:<\/p>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-3\" data-shcb-language-name=\"PostgreSQL SQL dialect and PL\/pgSQL\" data-shcb-language-slug=\"pgsql\"><span><code class=\"hljs language-pgsql\"><span class=\"hljs-keyword\">IF<\/span> :<span class=\"hljs-built_in\">NEW<\/span>.credit_limit &gt; :<span class=\"hljs-built_in\">OLD<\/span>.credit_limit <span class=\"hljs-keyword\">THEN<\/span>\n    <span class=\"hljs-comment\">-- carry an action<\/span>\n<span class=\"hljs-keyword\">END<\/span>;\n<\/code><\/span><small class=\"shcb-language\" id=\"shcb-language-3\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">PostgreSQL SQL dialect and PL\/pgSQL<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">pgsql<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<p>This table illustrates the availability of <code>:NEW<\/code> and <code>:OLD<\/code> variables by the triggering event:<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table><thead><tr><th>Triggering Event<\/th><th><code>:NEW<\/code><\/th><th><code>:OLD<\/code><\/th><\/tr><\/thead><tbody><tr><td><code>INSERT<\/code><\/td><td>Yes<\/td><td>No<\/td><\/tr><tr><td><code>UPDATE<\/code><\/td><td>Yes<\/td><td>Yes<\/td><\/tr><tr><td><code>DELETE<\/code><\/td><td>No<\/td><td>yes<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<h3 class=\"wp-block-heading\" id='modifying-old-new-values'>Modifying :OLD &amp; :NEW values <a href=\"#modifying-old-new-values\" class=\"anchor\" id=\"modifying-old-new-values\" title=\"Anchor for Modifying &lt;code&gt;:OLD&lt;\/code&gt; &amp; &lt;code&gt;:NEW&lt;\/code&gt; values\">#<\/a><\/h3>\n\n\n\n<p>A <code>BEFORE<\/code> row-level trigger can modify the new column values, but an <code>AFTER<\/code> row-level trigger cannot.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id='correlation-names'>Correlation names <a href=\"#correlation-names\" class=\"anchor\" id=\"correlation-names\" title=\"Anchor for Correlation names\">#<\/a><\/h3>\n\n\n\n<p><code>OLD<\/code> and <code>NEW<\/code> are the default correlation names. But you can override them using the <code>REFERENCING<\/code> clause.<\/p>\n\n\n\n<p>When you reference <code>OLD<\/code> and <code>NEW<\/code> in the trigger body, you must precede them with a colon (:) because <code>OLD<\/code> and <code>NEW<\/code> are external variable references.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id='performance-consideration'>Performance consideration <a href=\"#performance-consideration\" class=\"anchor\" id=\"performance-consideration\" title=\"Anchor for Performance consideration\">#<\/a><\/h3>\n\n\n\n<p>A row-level trigger fires each time a row is affected by a triggering event. For example, if you update 1000 rows in a table, the trigger will fire 1000 times, which potentially cause a performance issue.<\/p>\n\n\n\n<p>To specify a condition of when to fire the trigger, you can use the <code>WHEN<\/code> clause. For example, the following trigger only fires when you update credit for a customer with the new credit is greater than 10,000:<\/p>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-4\" data-shcb-language-name=\"PostgreSQL SQL dialect and PL\/pgSQL\" data-shcb-language-slug=\"pgsql\"><span><code class=\"hljs language-pgsql\"><span class=\"hljs-keyword\">CREATE<\/span> <span class=\"hljs-keyword\">OR REPLACE<\/span> <span class=\"hljs-keyword\">TRIGGER<\/span> \n    <span class=\"hljs-keyword\">BEFORE<\/span> <span class=\"hljs-keyword\">UPDATE<\/span> <span class=\"hljs-keyword\">OF<\/span> credit_limit \n    <span class=\"hljs-keyword\">ON<\/span> customers\n    <span class=\"hljs-keyword\">FOR<\/span> <span class=\"hljs-keyword\">EACH<\/span> <span class=\"hljs-keyword\">ROW<\/span> \n    <span class=\"hljs-keyword\">WHEN<\/span> <span class=\"hljs-built_in\">NEW<\/span>.credit_limit &gt; <span class=\"hljs-number\">10000<\/span>;\n...\n<\/code><\/span><small class=\"shcb-language\" id=\"shcb-language-4\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">PostgreSQL SQL dialect and PL\/pgSQL<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">pgsql<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<p>In some situations, using the condition in the <code>WHEN<\/code> can significantly improve the performance of the database.<\/p>\n\n\n\n<p>Note that you can use both <code>OLD<\/code> and <code>NEW<\/code> in the <code>WHEN<\/code> clause. In addition, you don&#8217;t use a colon (:) as the prefix for these variables.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id='oracle-row-level-trigger-example'>Oracle row-level trigger example <a href=\"#oracle-row-level-trigger-example\" class=\"anchor\" id=\"oracle-row-level-trigger-example\" title=\"Anchor for Oracle row-level trigger example\">#<\/a><\/h2>\n\n\n\n<p>We&#8217;ll use the <code>customers<\/code> table from the <a href=\"https:\/\/www.oracletutorial.com\/getting-started\/oracle-sample-database\/\">sample database<\/a> for demonstration:<\/p>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" decoding=\"async\" width=\"144\" height=\"145\" src=\"https:\/\/www.oracletutorial.com\/wp-content\/uploads\/2017\/07\/customers-table.png\" alt=\"customers table\" class=\"wp-image-298\"\/><\/figure>\n\n\n\n<p>The following example creates a row-level trigger that prevents users from updating credit for a customer if the new credit increases to more than double:<\/p>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-5\" data-shcb-language-name=\"PostgreSQL SQL dialect and PL\/pgSQL\" data-shcb-language-slug=\"pgsql\"><span><code class=\"hljs language-pgsql\"><span class=\"hljs-keyword\">CREATE<\/span> <span class=\"hljs-keyword\">OR REPLACE<\/span> <span class=\"hljs-keyword\">TRIGGER<\/span> customers_update_credit_trg \n    <span class=\"hljs-keyword\">BEFORE<\/span> <span class=\"hljs-keyword\">UPDATE<\/span> <span class=\"hljs-keyword\">OF<\/span> credit_limit\n    <span class=\"hljs-keyword\">ON<\/span> customers\n    <span class=\"hljs-keyword\">FOR<\/span> <span class=\"hljs-keyword\">EACH<\/span> <span class=\"hljs-keyword\">ROW<\/span>\n    <span class=\"hljs-keyword\">WHEN<\/span> (<span class=\"hljs-built_in\">NEW<\/span>.credit_limit &gt; <span class=\"hljs-number\">0<\/span>)\n<span class=\"hljs-keyword\">BEGIN<\/span>\n    <span class=\"hljs-comment\">-- check the credit limit<\/span>\n    <span class=\"hljs-keyword\">IF<\/span> :<span class=\"hljs-built_in\">NEW<\/span>.credit_limit &gt;= <span class=\"hljs-number\">2<\/span> * :<span class=\"hljs-built_in\">OLD<\/span>.credit_limit <span class=\"hljs-keyword\">THEN<\/span>\n        raise_application_error(<span class=\"hljs-number\">-20101<\/span>,<span class=\"hljs-string\">'The new credit '<\/span> || :<span class=\"hljs-built_in\">NEW<\/span>.credit_limit || \n            <span class=\"hljs-string\">' cannot increase to more than double, the current credit '<\/span> || :<span class=\"hljs-built_in\">OLD<\/span>.credit_limit);\n    <span class=\"hljs-keyword\">END<\/span> <span class=\"hljs-keyword\">IF<\/span>;\n<span class=\"hljs-keyword\">END<\/span>;\n<\/code><\/span><small class=\"shcb-language\" id=\"shcb-language-5\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">PostgreSQL SQL dialect and PL\/pgSQL<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">pgsql<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<p>First, specify the name of the trigger:<\/p>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-6\" data-shcb-language-name=\"PostgreSQL SQL dialect and PL\/pgSQL\" data-shcb-language-slug=\"pgsql\"><span><code class=\"hljs language-pgsql\"><span class=\"hljs-keyword\">CREATE<\/span> <span class=\"hljs-keyword\">OR REPLACE<\/span> <span class=\"hljs-keyword\">TRIGGER<\/span> customers_update_credit_trg \n<\/code><\/span><small class=\"shcb-language\" id=\"shcb-language-6\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">PostgreSQL SQL dialect and PL\/pgSQL<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">pgsql<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<p>Next, set the triggering event is <code>BEFORE UPDATE<\/code> of the <code>credit_limit<\/code> column on the <code>customers<\/code> table.<\/p>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-7\" data-shcb-language-name=\"PostgreSQL SQL dialect and PL\/pgSQL\" data-shcb-language-slug=\"pgsql\"><span><code class=\"hljs language-pgsql\"><span class=\"hljs-keyword\">BEFORE<\/span> <span class=\"hljs-keyword\">UPDATE<\/span> <span class=\"hljs-keyword\">OF<\/span> credit_limit\n<span class=\"hljs-keyword\">ON<\/span> customers\n<\/code><\/span><small class=\"shcb-language\" id=\"shcb-language-7\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">PostgreSQL SQL dialect and PL\/pgSQL<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">pgsql<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<p>Then, use the <code>FOR EACH ROW<\/code> to specify that the trigger is a row-level trigger.<\/p>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-8\" data-shcb-language-name=\"PostgreSQL SQL dialect and PL\/pgSQL\" data-shcb-language-slug=\"pgsql\"><span><code class=\"hljs language-pgsql\"><span class=\"hljs-keyword\">FOR<\/span> <span class=\"hljs-keyword\">EACH<\/span> <span class=\"hljs-keyword\">ROW<\/span>\n<\/code><\/span><small class=\"shcb-language\" id=\"shcb-language-8\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">PostgreSQL SQL dialect and PL\/pgSQL<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">pgsql<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<p>After that, specify the condition that fires trigger only when the new credit is greater than zero in the <code>WHEN<\/code> clause:<\/p>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-9\" data-shcb-language-name=\"PostgreSQL SQL dialect and PL\/pgSQL\" data-shcb-language-slug=\"pgsql\"><span><code class=\"hljs language-pgsql\"><span class=\"hljs-keyword\">WHEN<\/span> (<span class=\"hljs-built_in\">NEW<\/span>.credit_limit &gt; <span class=\"hljs-number\">0<\/span>)\n<\/code><\/span><small class=\"shcb-language\" id=\"shcb-language-9\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">PostgreSQL SQL dialect and PL\/pgSQL<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">pgsql<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<p>Finally, check the new credit from the <code>:NEW<\/code> variable with the current credit from the <code>:OLD<\/code> variable, call the procedure <code>raise_application_error<\/code> to raise an error if it is.<\/p>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-10\" data-shcb-language-name=\"PostgreSQL SQL dialect and PL\/pgSQL\" data-shcb-language-slug=\"pgsql\"><span><code class=\"hljs language-pgsql\"><span class=\"hljs-keyword\">IF<\/span> :<span class=\"hljs-built_in\">NEW<\/span>.credit_limit &gt;= <span class=\"hljs-number\">2<\/span> * :<span class=\"hljs-built_in\">OLD<\/span>.credit_limit <span class=\"hljs-keyword\">THEN<\/span>\n        raise_application_error(<span class=\"hljs-number\">-20101<\/span>,<span class=\"hljs-string\">'The new credit '<\/span> || :<span class=\"hljs-built_in\">NEW<\/span>.credit_limit || \n            <span class=\"hljs-string\">' cannot increase to more than double, the current credit '<\/span> || :<span class=\"hljs-built_in\">OLD<\/span>.credit_limit);\n<span class=\"hljs-keyword\">END<\/span> <span class=\"hljs-keyword\">IF<\/span>;\n<\/code><\/span><small class=\"shcb-language\" id=\"shcb-language-10\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">PostgreSQL SQL dialect and PL\/pgSQL<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">pgsql<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<h3 class=\"wp-block-heading\" id='testing-the-trigger'>Testing the trigger <a href=\"#testing-the-trigger\" class=\"anchor\" id=\"testing-the-trigger\" title=\"Anchor for Testing the trigger\">#<\/a><\/h3>\n\n\n\n<p>First, find the credit limit of the customer id 10:<\/p>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-11\" data-shcb-language-name=\"PostgreSQL SQL dialect and PL\/pgSQL\" data-shcb-language-slug=\"pgsql\"><span><code class=\"hljs language-pgsql\"><span class=\"hljs-keyword\">SELECT<\/span> credit_limit \n<span class=\"hljs-keyword\">FROM<\/span> customers \n<span class=\"hljs-keyword\">WHERE<\/span> customer_id = <span class=\"hljs-number\">10<\/span>;\n<\/code><\/span><small class=\"shcb-language\" id=\"shcb-language-11\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">PostgreSQL SQL dialect and PL\/pgSQL<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">pgsql<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<p>Here is the output:<\/p>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-12\" data-shcb-language-name=\"PostgreSQL SQL dialect and PL\/pgSQL\" data-shcb-language-slug=\"pgsql\"><span><code class=\"hljs language-pgsql\">CREDIT_LIMIT\n<span class=\"hljs-comment\">------------<\/span>\n       <span class=\"hljs-number\">2000<\/span>\n<\/code><\/span><small class=\"shcb-language\" id=\"shcb-language-12\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">PostgreSQL SQL dialect and PL\/pgSQL<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">pgsql<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<p>Second, update the credit of the customer 10 to 5000:<\/p>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-13\" data-shcb-language-name=\"PostgreSQL SQL dialect and PL\/pgSQL\" data-shcb-language-slug=\"pgsql\"><span><code class=\"hljs language-pgsql\"><span class=\"hljs-keyword\">UPDATE<\/span> customers\n<span class=\"hljs-keyword\">SET<\/span> credit_limit = <span class=\"hljs-number\">5000<\/span>\n<span class=\"hljs-keyword\">WHERE<\/span> customer_id = <span class=\"hljs-number\">10<\/span>;\n<\/code><\/span><small class=\"shcb-language\" id=\"shcb-language-13\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">PostgreSQL SQL dialect and PL\/pgSQL<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">pgsql<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<p>The output is as follows:<\/p>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-14\" data-shcb-language-name=\"PostgreSQL SQL dialect and PL\/pgSQL\" data-shcb-language-slug=\"pgsql\"><span><code class=\"hljs language-pgsql\">ORA<span class=\"hljs-number\">-20101<\/span>: The <span class=\"hljs-built_in\">new<\/span> credit <span class=\"hljs-number\">5000<\/span> cannot increase more than <span class=\"hljs-type\">double<\/span>, the <span class=\"hljs-keyword\">current<\/span> credit <span class=\"hljs-number\">2000<\/span>\nORA<span class=\"hljs-number\">-06512<\/span>: at \"OT.CUSTOMERS_UPDATE_CREDIT_TRG\", <span class=\"hljs-type\">line<\/span> <span class=\"hljs-number\">4<\/span>\nORA<span class=\"hljs-number\">-04088<\/span>: error during execution <span class=\"hljs-keyword\">of<\/span> <span class=\"hljs-keyword\">trigger<\/span> <span class=\"hljs-string\">'OT.CUSTOMERS_UPDATE_CREDIT_TRG'<\/span>\n<\/code><\/span><small class=\"shcb-language\" id=\"shcb-language-14\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">PostgreSQL SQL dialect and PL\/pgSQL<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">pgsql<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<p>It means that the trigger <code>customers_update_credit_trg<\/code> has been fired as expected.<\/p>\n\n\n\n<p>In this tutorial, you have learned about Oracle row-level triggers and how to use the <code>CREATE TRIGGER<\/code> statement to create a new row-level trigger.<\/p>\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=\"2909\"\n\t\t\t\tdata-post-url=\"https:\/\/www.oracletutorial.com\/plsql-tutorial\/oracle-row-level-triggers\/\"\n\t\t\t\tdata-post-title=\"Oracle Row-level Triggers\"\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 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row-level trigger.<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":1418,"menu_order":35,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-2909","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>Oracle Row-level Triggers<\/title>\n<meta name=\"description\" content=\"Learn about Oracle row-level triggers and how to use the CREATE TRIGGER statement to create new row-level triggers.\" \/>\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.oracletutorial.com\/plsql-tutorial\/oracle-row-level-triggers\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Oracle Row-level 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