- #Sqlite insert duplicate to unique how to#
- #Sqlite insert duplicate to unique update#
- #Sqlite insert duplicate to unique full#
- #Sqlite insert duplicate to unique code#
Inserting NULL primary keys into src causes them to be given auto-generated values.Ī "CREATE TABLE. This example works because the table "tmp" has no primary key constraint, but "src" does. To only duplicate a desired row, simply add a WHERE clause to the first line. The above example duplicates all rows of the table "src". To duplicate the rows of "src", use the following SQL in SQLite3: CREATE TEMPORARY TABLE tmp AS SELECT * FROM src In this example I assume that there is an existing, populated, table called "src" with an INTEGER PRIMARY KEY called "id", as well as several other columns. The trick is to create a temporary table using the "CREATE TABLE AS" syntax.
#Sqlite insert duplicate to unique how to#
In this tutorial, we have shown you how to use the SQLite REPLACE statement to insert or replace a row in a table.This can be done using * syntax without having to know the schema of the table (other than the name of the primary key). If the title column does not have the NOT NULL constraint, the REPLACE statement will insert a new row whose the title column is NULL. Therefore, SQLite rolls back the transaction. However, it violates the NOT NULL constraint of the title column. Then, SQLite tried to insert a new row with two columns: ( id, min_salary).
#Sqlite insert duplicate to unique update#
What the statement tried to do is to update the min_salary for the position with id 2, which is the developer.įirst, the position with id 2 already exists, the REPLACE statement removes it.
#Sqlite insert duplicate to unique code#
VALUES( 2, 110000) Code language: SQL (Structured Query Language) ( sql ) Notice that the REPLACE statement means INSERT or REPLACE, not INSERT or UPDATE. Third, SQLite inserted a new row with the data provided by the REPLACE statement. Second, because this statement violated the UNIQUE constraint by trying to add the DBA title that already exists, SQLite deleted the existing row. REPLACE INTO positions (title, min_salary)Ĭode language: SQL (Structured Query Language) ( sql )įirst, SQLite checked the UNIQUE constraint. Positions Code language: SQL (Structured Query Language) ( sql ) You can verify the REPLACE operation using the SELECT statement. VALUES( 'Full Stack Developer', 140000) Code language: SQL (Structured Query Language) ( sql ) REPLACE INTO positions (title, min_salary)
#Sqlite insert duplicate to unique full#
The following REPLACE statement inserts a new row into the positions table because the position title Full Stack Developer is not in the positions table. Suppose, you want to add a position into the positions table if it does not exist, in case the position exists, update the current one. ON positions (title) Code language: SQL (Structured Query Language) ( sql ) The following statement creates a unique index on the title column of the positions table to ensure that it doesn’t have any duplicate position title: CREATE UNIQUE INDEX idx_positions_title SELECT * FROM positions Code language: SQL (Structured Query Language) ( sql ) Third, verify the insert using the following SELECT statement. ( 'Architect', 150000) Code language: SQL (Structured Query Language) ( sql ) INSERT INTO positions (title, min_salary) Second, insert some rows into the positions table. ) Code language: SQL (Structured Query Language) ( sql ) The SQLite REPLACE statement examplesįirst, create a new table named positions with the following structure. Let’s take a look at some examples of using the SQLite REPLACE statement to understand how it works. Or in a short form: REPLACE INTO table(column_list) VALUES(value_list) Code language: SQL (Structured Query Language) ( sql ) INSERT OR REPLACE INTO table(column_list) The following illustrates the syntax of the REPLACE statement. In the second step, if any constraint violation e.g., NOT NULL constraint occurs, the REPLACE statement will abort the action and roll back the transaction. First, delete the existing row that causes a constraint violation.
The idea of the REPLACE statement is that when a UNIQUE or PRIMARY KEY constraint violation occurs, it does the following: Introduction to the SQLite REPLACE statement
Summary: in this tutorial, you will learn how to use the SQLite REPLACE statement to insert or replace the existing row in a table.
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