In such a case, the INSERT INTO statement will execute, and the non-existing record will be inserted into the specified table. If the given record doesn’t exist in the selected table, then the sub-query will retrieve “ True”. For this purpose, use the NOT EXISTS option within the WHERE Clause. So alternatively, you can use the subquery to check the existence of a specific record in a table. PostgreSQL doesn’t offer the “IF NOT EXISTS” option for the INSERT INTO statement. This is how you can achieve the functionality of INSERT IF NOT EXISTS in PostgreSQL. You can verify the inserted that using the following command: SELECT * FROM emp_tab The output proves that the non-existing record has been inserted into the emp_tab successfully. SELECT emp_id FROM emp_tab WHERE emp_id = 5 Let’s execute the INSERT command one more time to insert a non-existing record into the “emp_tab” table: INSERT INTO emp_tab(emp_id, emp_name, emp_email) The output proves that the “emp_id = 3” already exists in the “emp_tab”, so the INSERT command didn’t insert that record into the targeted table. Let’s run the SELECT statement to see if the selected record has been inserted into the emp_tab or not: SELECT * FROM emp_tab SELECT emp_id FROM emp_tab WHERE emp_id = 3 Let’s execute the below query to insert non-existing records in the emp_tab: INSERT INTO emp_tab(emp_id, emp_name, emp_email) The output shows that four records have been inserted into the emp_tab successfully.Įxample 3: Inserting Non-Existing Records You can verify the newly inserted data using the below-mentioned command: SELECT * FROM emp_tab VALUES (1, 'Joseph', 'Tim', 'Anna', 'Henry', output proves that four records have been inserted into the “emp_tab” successfully. Let’s insert some data into the emp_tab using the INSERT query: INSERT INTO emp_tab(emp_id, emp_name, emp_email) The emp_tab has been created successfully. You can verify the table’s creation via the SELECT command: SELECT * FROM emp_tab The resultant message verifies the working of CREATE TABLE statements. The emp_id will take a numeric value, while emp_name and emp_email will take character values: In this example, we created a table named emp_tab that consists of three columns. Let’s create a sample table via CREATE TABLE command: CREATE TABLE emp_tab( If the record to be inserted doesn’t exist in the selected table, then the sub-query will retrieve “True”. In the above syntax, the NOT EXIST operator/clause is used within the WHERE Clause, which will check the existence of a record. SELECT col_name FROM tab_name WHERE condition The below syntax will guide you on how to achieve the functionality of the “IF NOT EXISTS” option using a subquery: INSERT INTO tab_name(col_list) How to Use Subquery to Insert Non-existing Values in a Table? Using the INSERT statement, users can insert as many records as they want using the comma-separated syntax.īut what if a user wants to insert only those records that do not already exist in the selected table? How does Postgres deal with such situations? Well! In PostgreSQL, the INSERT statement doesn’t support the “IF NOT EXISTS” option. In PostgreSQL, the INSERT INTO statement is used to insert the data into any specific table. Inserting data into tables is a very common operation in any database management system.
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