![]() If a table has a CHECK constraint on it, and you try to insert or update data that violates the CHECK constraint, the operation will fail with an error. Other databases such as PostgreSQL would let you use RegExp using the ~ operator. In SQLite, you can create a CHECK constraint by adding the applicable code within the CREATE TABLE statement when creating the table. By default, the REGEXP operator has no implementation in SQLite. You can find more information and instructions at Stack Overflow's How do I use regex in a SQLite query?. The type of an existing database can be checked from the SQLITE debug info value OGR. However, to be able to use it, you first need to install the sqlite3-pcre pcre regex extension for sqlite3, on a Linux machine (there may be a Windows alternative, but I've not been able to find it). ![]() If the new column has a NOT NULL constraint, you must specify a default value for the column other than a NULL value. You can actually use a REGEXP operator and write: CHECK (prefix REGEXP '^+$') The new column cannot have a UNIQUE or PRIMARY KEY constraint. The only thing it will complain about are statements like: INSERT INTO test We can use two types of constraints, that is column level or table level constraint. This means your CHECK condition, as originally written, is not actually checking what you expect. SQLite Constraint Last update on Aug21:50:40 (UTC/GMT +8 hours) What is Constraint The CONSTRAINTS are an integrity which defines some conditions that restrict the column to contain the true data while inserting or updating or deleting. ![]() * in a regexp, and _ meaning (1 of anything), which would be the equivalentof. Actually, you have two metacharacters: % means (0 or more of anything), which would be the equivalent of a. The pattern matches allowed by this operator are very simple, compared to the powerful regexp. Once we create a table and set CHECK constraint to insert data in the table using the following statement. The LIKE operator in SQL does not work like regular expressions. Here in the above example we added CHECK constraint to the PRICE column to check whether the inserting or updating values greater than zero or not. 3 years ago Port to EF Core 6.0 2 years ago Bump from 17.4.1 to 17.5.0 ( 102) last month Option added to disable regular expression constraints.
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