将NOT_NULL约束添加到SQL列 [英] Adding the NOT_NULL constraint to an SQL column
问题描述
我正在尝试使用以下方式将NOT_NULL约束添加到SQL h2数据库中的列中:
I'm trying to add the NOT_NULL constraint to a column in an SQL h2 database, using
ALTER TABLE CHARACTERS ADD CONSTRAINT nn_PID NOT_NULL (PLAYER_ID);
这与我在此处找到的模式:
This follows the pattern I found here:
ALTER TABLE Persons ADD CONSTRAINT pk_PersonID PRIMARY KEY (P_Id,LastName)
除了我更改约束,表和列名称.但是我得到这个错误:
Except I change the constraint, table and column names. But I get this error:
SQL语句中的语法错误"ALTER TABLE CHARACTERS ADD CONSTRAINT NN_PID NOT_NULL [*](PLAYER_ID)";预期的.,评论,主要,索引,键,支票,唯一,外国"; SQL语句: 更改表字符添加约束nn_PID NOT_NULL(PLAYER_ID)[42001-168] 42001/42001(帮助)
Syntax error in SQL statement "ALTER TABLE CHARACTERS ADD CONSTRAINT NN_PID NOT_NULL[*] (PLAYER_ID) "; expected "., COMMENT, PRIMARY, INDEX, KEY, CHECK, UNIQUE, FOREIGN"; SQL statement: ALTER TABLE CHARACTERS ADD CONSTRAINT nn_PID NOT_NULL (PLAYER_ID) [42001-168] 42001/42001 (Help)
如何添加NOT_NULL约束?
How can I add the NOT_NULL constraint?
推荐答案
来自 H2 SQL语法:
ALTER TABLE TEST ALTER COLUMN NAME SET NOT NULL;
因此我们可以使用:
ALTER TABLE CHARACTERS ALTER PLAYER_ID SET NOT NULL;
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