可以使用CREATE INDEX语句向表中添加单字段或多字段的索引,并且可以使用 ALTER TABLE 或者DROP语句删除使用 ALTER TABLE 或 CREATE INDEX 创建的索引。 可以对单个字段或在应用于单个字段或多字段的命名 CONSTRAINT 的命名 CONSTRAINT 子句中使用 NOT NULL。 但是,仅可以对字段应用一次 NOT NULL 限制。 尝试多次应用此...
ALTER TABLE [ database_name . [ schema_name ] . | schema_name . ] table_name { ALTER COLUMN column_name { [ type_schema_name. ] type_name [ ( { precision [ ,scale ] | max | xml_schema_collection } ) ] [ COLLATE collation_name ] [ SPARSE | NULL | NOT NULL ] | {ADD |...
以下能够删除一列的是 ( ) A. alter table emp remove addcolumn B. alter table emp drop column addcolumn C. alter table emp delete column addcolumn D. alter table E. mp delete addcolumn 答案: B 相关知识点: 试题来源: 解析 D.alter table 反馈 收藏 ...
百度试题 题目下列能够删除一列的是() A.alter table emp remove columnB.alter table emp drop columnC.alter table emp delete columnD.alter table emp delete and drop addcolumn相关知识点: 试题来源: 解析 B 反馈 收藏
If you are not the owner of the table, then you need theDROPANYTABLEprivilege in order to use thedrop_table_partitionortruncate_table_partitionclause. You must also have space quota in the tablespace in which space is to be acquired in order to use theadd_table_partition,modify_table_parti...
在MySQL 中, 以下能够删除一列的SQL语句是( )A.ALTER TABLE emp REMOVE addcolumnB.ALTER TABLE emp DROP
TABLE tbl_name [{WITH | WITHOUT} VALIDATION] | ANALYZE PARTITION {partition_names | ALL} | CHECK PARTITION {partition_names | ALL} | OPTIMIZE PARTITION {partition_names | ALL} | REBUILD PARTITION {partition_names | ALL} | REPAIR PARTITION {partition_names | ALL} | REMOVE PARTITIONING | ...
百度试题 题目下列能够删除一列的命令是A.alter table emp remove addcolumnB.alter table emp delete column addcolumnC.alter table emp drop column addcolumnD.alter table emp delete addcolumn 相关知识点: 试题来源: 解析 C 反馈 收藏
Usage of ALTER TABLE,Hologres:You can execute the ALTER TABLE statement to modify a table. Modifications made to a parent table are automatically applied to its child tables. This topic describes how to use the ALTER TABLE stateme...
NullNotNull NumericLiteral OdbcConvertSpecification OdbcFunctionCall OdbcLiteral OdbcLiteralType OdbcQualifiedJoinTableReference OffsetClause OnFailureAuditOption OnlineIndexLowPriorityLockWaitOption OnlineIndexOption OnOffAssemblyOption OnOffAtomicBlockOption OnOffAuditTargetOption OnOffDatabase...