check-constraints

SQL Sub queries in check constraint

由 有些话、适合烂在心里 提交于 2019-11-26 14:18:41
问题 Can I make SQL sub queries in Check constraint ? I've a post table with columns id, owner I've another table action with columns user_id, post_id Table user with columns id post_id -> post.id and user_id -> user.id also post.owner -> user.id Now I want to constraint post(post_id).id != user_id on table action How is that possible ? 回答1: It is not supported to look beyond the current row in a CHECK constraint. http://www.postgresql.org/docs/9.1/interactive/sql-createtable.html says: A check

CHECK constraint in MySQL is not working

由 本秂侑毒 提交于 2019-11-26 10:57:56
First I created a table like CREATE TABLE Customer ( SD integer CHECK (SD > 0), Last_Name varchar (30), First_Name varchar(30) ); and then inserted values in that table INSERT INTO Customer values ('-2','abc','zz'); MySQL doesn't show an error, it accepted the values. David Kerins MySQL 8.0.16 is the first version that supports CHECK constraints. Read https://dev.mysql.com/doc/refman/8.0/en/create-table-check-constraints.html If you use MySQL 8.0.15 or earlier, the MySQL Reference Manual says: The CHECK clause is parsed but ignored by all storage engines. Try a trigger... mysql> delimiter //

Sub queries in check constraint

由 落爺英雄遲暮 提交于 2019-11-26 05:33:18
问题 I have table designed in SQL-Server 2008 R2. I have a column in that table which needs to be checked against another table when data is inserting. ALTER TABLE Table1 WITH CHECK ADD CONSTRAINT CK_Code CHECK (MyField in (Select Field From Table2)) This cause an error Sub-queries are not allowed in this context. Only scalar expressions are allowed. I have looked at this question about Check Constraint - Subqueries are not allowed in this context. Is there any way of achieving this without using

CHECK constraint in MySQL is not working

由 给你一囗甜甜゛ 提交于 2019-11-26 02:15:13
问题 First I created a table like CREATE TABLE Customer ( SD integer CHECK (SD > 0), Last_Name varchar (30), First_Name varchar(30) ); and then inserted values in that table INSERT INTO Customer values (\'-2\',\'abc\',\'zz\'); MySQL doesn\'t show an error, it accepted the values. 回答1: MySQL 8.0.16 is the first version that supports CHECK constraints. Read https://dev.mysql.com/doc/refman/8.0/en/create-table-check-constraints.html If you use MySQL 8.0.15 or earlier, the MySQL Reference Manual says:

CHECK constraint in MySQL is not working

由 依然范特西╮ 提交于 2019-11-25 21:40:01
问题 First I created a table like CREATE TABLE Customer ( SD integer CHECK (SD > 0), Last_Name varchar (30), First_Name varchar(30) ); and then inserted values in that table INSERT INTO Customer values (\'-2\',\'abc\',\'zz\'); MySQL doesn\'t show an error, it accepted the values. 回答1: MySQL 8.0.16 is the first version that supports CHECK constraints. Read https://dev.mysql.com/doc/refman/8.0/en/create-table-check-constraints.html If you use MySQL 8.0.15 or earlier, the MySQL Reference Manual says:
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