Here is the error message: Result: CHECK constraint failed: contacts
#SQLITESTUDIO ADVANCED CHECK CONSTRAINTS CODE#
VALUES( 'John', 'Doe', '408123456') Code language: SQL (Structured Query Language) ( sql )
If you attempt to execute the following statement, you will get a constraint violation error: INSERT INTO contacts(first_name, last_name, phone) This CHECK constraint ensures that the values in the phone column must be at least 10 characters. In the contacts table, the phone column has a CHECK constraint: CHECK ( length(phone) >= 10) Phone TEXT NOT NULL CHECK ( length(phone) >= 10) The following statement creates a new table named contacts: CREATE TABLE contacts ( 1) Using SQLite CHECK constraint at the column level example Let’s take some examples of using the CHECK constraints. Note that the expression of a CHECK constraint cannot contain a subquery. If the result is a non-zero value or NULL, it means no constraint violation occurred. If the result is zero, then a constraint violation occurred. In this syntax, whenever a row is inserted into a table or an existing row is updated, the expression associated with each CHECK constraint is evaluated and returned a numeric value 0 or 1.
#SQLITESTUDIO ADVANCED CHECK CONSTRAINTS HOW TO#
The following statement shows how to define a CHECK constraint at the column level: CREATE TABLE table_name(Ĭode language: SQL (Structured Query Language) ( sql )Īnd the following statement illustrates how to define a CHECK constraint at the table level: CREATE TABLE table_name(
SQLite allows you to define a CHECK constraint at the column level or the table level. The CHECK constraints allow you to define additional data integrity checks beyond UNIQUE or NOT NULL to suit your specific application. If the values do not meet the criteria defined by the expression, SQLite will issue a constraint violation and abort the statement. SQLite CHECK constraints allow you to define expressions to test values whenever they are inserted into or updated within a column. Summary: in this tutorial, you will learn how to use SQLite CHECK constraint to validate data before insert or update.
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