ALTER TABLE - DROP COLUMN To delete a column in a table, use the following syntax (notice that some database systems don't allow deleting a column): ALTERTABLEtable_name DROPCOLUMNcolumn_name; The following SQL
table_name | schema_name.table_name | table_name } [ AS FileTable ] ( { <column_definition> | <computed_column_definition> | <column_set_definition> | [ <table_constraint> ] [ ,... n ] | [ <table_index> ] } [ ,... n ] [ PERIOD FOR SYSTEM_TIME ( system_start_time_...
[Table(Name="dbo.dnt_users")] publicpartialclassUserinfo : INotifyPropertyChanging, INotifyPropertyChanged { dnt_users是数据库中的物理表.而我们的产品有一个特性,就是允许用户定制表名称的前缀.其实"dnt_" 就是表的前缀名.而这个值(前缀)是通过产品中的Tableprefix属性获取的.Tableprefix属性返回的值是通过 ...
table_name | table_name } { ALTER COLUMN column_name { [ type_schema_name. ] type_name [ ( { precision [ , scale ] | max | xml_schema_collection } ) ] [ COLLATE collation_name ] [ NULL | NOT NULL ] [ SPARSE ] | { ADD | DROP } { ROWGUIDCOL | PERSISTED | NOT FOR ...
FOR ( @variable_name { UNKNOWN | = <literal_constant> } [ , ...n ] ) | OPTIMIZE FOR UNKNOWN | PARAMETERIZATION { SIMPLE | FORCED } | QUERYTRACEON <integer_value> | RECOMPILE | ROBUST PLAN | USE HINT ( 'hint_name...
table_name | table_name } [ AS FileTable ] ( { <column_definition> | <computed_column_definition> | <column_set_definition> | [ <table_constraint> ] [ ,... n ] | [ <table_index> ] } [ ,... n ] [ PERIOD FOR SYSTEM_TIME ( system_start_time_column_name , system_end_time...
FOR ( @variable_name { UNKNOWN | = <literal_constant> } [ , ...n ] ) | OPTIMIZE FOR UNKNOWN | PARAMETERIZATION { SIMPLE | FORCED } | QUERYTRACEON <integer_value> | RECOMPILE | ROBUST PLAN | USE HINT ( 'hint_name' [ , ...n ] ) | USE PLAN N'<xml_plan>' | ...
Use the ALTER TABLE statement to alter the definition of a nonpartitioned table, a partitioned table, a table partition, or a table subpartition. For object tables or relational tables with object columns, use ALTER TABLE to convert the table to the latest definition of its referenced type ...
--WHERE table_name = :tname AND table_owner = :towner ORDER BY partition_position 12.查看还没提交的事务 select * from v$locked_object; select * from v$transaction; 13。查找object为哪些进程所用 select p.spid, s.sid, s.serial# serial_num, ...
OPTIMIZEFOR( @variable_name{UNKNOWN| =<literal_constant>} [ , ...n ] ) |OPTIMIZEFORUNKNOWN|PARAMETERIZATION{SIMPLE|FORCED} |QUERYTRACEON<integer_value>|RECOMPILE|ROBUSTPLAN|USEHINT('hint_name'[ , ...n ] ) |USEPLANN'<xml_plan>'|TABLEHINT(<exposed_object_name>[ ,<table_hint>[ [ ,...