SQL_AD_DROP_DOMAIN_CONSTRAINT = <支持删除域约束子句> (完全级别)SQL_AD_DROP_DOMAIN_DEFAULT = <支持更改域><删除域默认子句> (完全级别)如果<支持添加域约束>,则以下位指定受支持的<约束属性>(设置SQL_AD_ADD_DOMAIN_CONSTRAINT位):SQL_AD_ADD_CONSTRAINT_DEFERRABLE
SQL_AD_ADD_CONSTRAINT_INITIALLY_DEFERRED (全級)SQL_AD_ADD_CONSTRAINT_INITIALLY_IMMEDIATE (全級) SQL_ALTER_TABLE 2.0 SQLUINTEGER 位掩碼,列舉數據源所支援的 ALTER TABLE 語句中的 子句。每個位掩碼旁的括弧中會顯示必須支援此功能的SQL-92 或 FIPS 一致性層級。下列位掩碼可用來判斷支援的子句:SQL_AT_...
(Optional) Used to specify or control the generation of a foreign key constraint when table generation is in effect. boolean insertable default true (Optional) Whether the column is included in SQL INSERT statements generated by the persistence provider. ...
where 子句不仅仅支持 "where 列名 = 值" 这种名等于值的查询形式, 对一般的比较运算的运算符都是支持的, 例如 =、>、<、>=、<、!= 以及一些扩展运算符 is [not] null、in、like 等等。 还可以对查询条件使用 or 和 and 进行组合查询, 以后还会学到更加高级的条件查询方式, 这里不再多做介绍。 示例:...
SQL_AD_ADD_CONSTRAINT_DEFERRABLE (Full level)SQL_AD_ADD_CONSTRAINT_NON_DEFERRABLE (Full level)SQL_AD_ADD_CONSTRAINT_INITIALLY_DEFERRED (Full level)SQL_AD_ADD_CONSTRAINT_INITIALLY_IMMEDIATE (Full level) SQL_ALTER_TABLE 2.0 An SQLUINTEGER bitmask enumerating the clauses in the ALTER TABLE statement...
Because of this, constraint handling is a bit different in MySQL than in other DBMSs. We must handle the case when you have inserted or updated a lot of rows in a nontransactional table for which changes cannot be rolled back when an error occurs. ...
In most cases you would also want to attach a UNIQUE or PRIMARY KEY constraint to prevent duplicate values from being inserted unexpectedly. Lastly, the sequence is marked as "owned by" the column, so that it will be dropped if the column or table is dropped. Currently, the SERIAL column...
constraintfk_mas_detforeign key (master_id) references t_master(object_id) )partition by reference(fk_mas_det) ORA-14652:不支持引用分区外键 我们收到了一个Oracle报错。首先我们看一下定义reference partition的语法,在create table语句中要创建定义好外键约束的名称。之后,利用partition by语句,将外键作为划...
an integer column is created and its default value plans to be read from a sequencer. a not null constraint is used to ensure null is not inserted. in most cases you would also want to attach a unique or primary key constraint to prevent duplicate values from being inserted unexpectedly. ...
The mandatory roles and internal uniqueness constraints declare that each file is in exactly one folder, has exactly one (local) filename, and has exactly one size. The external uniqueness constraint can be used to provide a compound reference scheme and may be verbalized as shown. Sign in to...