PostgreSQL INSERT

 Summary: in this tutorial, you will learn how to insert new rows into a table using the PostgreSQL INSERT statement.

When you create a new table, it does not have any data. The first thing you often do is to insert new rows into the table. PostgreSQL provides the INSERT statement that allows you to insert one or more rows into a table at a time.

PostgreSQL INSERT syntax

The following illustrates the syntax of the INSERT statement:

First, you specify the name of the table that you want to insert a new row after the INSERT INTO clause, followed by a comma-separated column list.

Second, you list a comma-separated value list after the VALUES clause. The value list must be in the same order as the columns list specified after the table name.

To add multiple rows into a table at a time, you use the following syntax:

You just need to add additional comma-separated value lists after the first list, each value in the list is separated by a comma (,).

To insert data that comes from another table, you use the INSERT INTO SELECT statement as follows:

The WHERE clause is used to filter rows that allow you to insert partial data from the another_table into the table.

PostgreSQL INSERT examples

Let’s create a new table named linkfor the demonstration.

You will learn how to create a new table in the later tutorial, just execute the statement for now.

PostgreSQL insert one-row examples

The following statement inserts a new row into the linktable:

To insert character data type, you must enclose it in single quotes (‘). For the number data type, you do not need to do so, just you a plain number.

If you omit any column that accepts the NULLvalue in the INSERT statement, the column will take its default value. In case the default value is not set for the column, the column will take the NULL value.

PostgreSQL provides a value for the serial column automatically so you do not and should not insert a value for the serial column.

You can verify the inserted row by using the SELECT statement:

If you want to insert a string that contains a single quote character such as O’Reilly media, you have to use a single quote (‘) escape character as the following query:

PostgreSQL insert multiple rows example

The following statement inserts multiple rows into the linktable at a time:

PostgreSQL insert date example

Let’s add a new column named last_updateinto the linktable and set its default value to CURRENT_DATE.

The following statement inserts a new row with specified date into the linktable. The date format is YYYY-MM-DD.

You can also use the DEFAULTkeyword to set the default value for the date column, or any column that has a default value.

PostgreSQL insert data from another table example

First, create another table named link_tmpthat has the same structure as the linktable:

Second, insert rows from the link table whose values of the date column are not NULL:

Third, verify the insert operation by querying data from the link_tmptable:

Get the last insert id

To get the last insert id from the table after inserting a new row, you use the RETURNINGclause in the INSERTstatement. This is a PostgreSQL extension to SQL.
The following statement inserts a new row into the linktable and returns the last insert id:

The id matches with the last insert id in the linktable:

In this tutorial, you have learned how to use the PostgreSQL INSERT statement to insert new rows into a table.