Syscat.checks Contains a row for each table check constraint db2 select constname, tabname, text from syscat.checks.
checks为每个表检查约束保持一个行db2select constname,tabname,textfrom syscat . checks。
SYSCAT.COLCHECKS Contains a row for each column that is referenced by a table check constraint db2 select constname, tabname, colname, usage from syscat.colchecks
COLCHECKS为表检查约束所引用的每个列保持一个行db2select constname,tabname,colname,usage from syscat.colchecks
For table, use the CHECK constraint to ensure integrity.
对于表,可以使用CHECK约束来确保完整性。
The CHECK constraint is perfect for this, as the following table definition shows.
CHECK约束非常适合执行此项操作,如以下所示表定义。
If an XML validation check constraint exists on the XML column of the table, the user may need to validate the new XML value before the update either manually or by creating a trigger.
如果在表的xml列上存在XML验证检查约束,在手动更新或者通过触发器更新之前,用户可能需要验证新的xml值。
The before trigger and check constraint on a table XML value always ensures that the XML values are valid as per the specified schema.
对一个表XML值应用before trigger和检查约束,往往可以确保 XML值对于指定模式是有效的。
Syscat.tabconst Contains a row for each unique (u), primary key (p), foreign key (f), or table check (k) constraint db2 select constname, tabname, type from syscat.tabconst.
tabconst为每个唯一性(U)、主键(p)、外键(f)或者表检查(K)约束保持一个行db2select constname,tabname,typefrom syscat . tabconst。
In Oracle 10g, if there is a BEFORE INSERT TRIGGER and a NOT NULL constraint on a table, then the BEFORE TRIGGER is executed first, and then the constraint check is performed.
在Oracle10g中,如果表上同时存在BEFORE INSERT触发器和NOT NULL约束,那么先执行BEFORE触发器,然后执行约束检查。
A check constraint is a type of constraint which can be put on a table column at the time of the creation of the table.
检查约束(check constraint)是一类可以在创建表时作用到表列的约束。
Creating a table with check constraint on an XML column.
创建一个xml列包含检查限制的表。
A check constraint specifies the data values or formats that are acceptable in one or more columns in a table.
检查条件约束可指定在资料表中为一或多个资料行所接受的资料值或格式。
A check constraint specifies the data values or formats that are acceptable in one or more columns in a table.
检查条件约束可指定在资料表中为一或多个资料行所接受的资料值或格式。
应用推荐