335 336 ALTER COLUMN 可以为一列指定一个新的缺省值或删除老的缺省值。如果老的缺省值被移除且列可以被设为 NULL,新的缺省值将是 NULL。如果该列不允许有 NULL值,MySQL 以章节 6.5.3 CREATE TABLE 句法 中的描述方式为该列赋于一个缺省值。 337 338 DROP INDEX 移除一个索引。这是 MySQL 对 A
若要建立分割區配置,請參閱 CREATE PARTITION SCHEME (Transact-SQL)。 column_name 指定分割索引分割的數據行。 此資料行必須符合 partition_scheme_name 所使用資料分割函數引數的資料類型、長度與有效位數。 filegroup_name 指定用來儲存叢集數據行存放區索引的檔案群組。 如果未指定任何位置且數據表未分割,...
5 INLINE LENGTH only applies to a column with a LOB data type or a distinct type that is based on a LOB data type. data-type: built-in-typedistinct-type-name built-in-type: SMALLINTINTEGERINTBIGINTDECIMALDECNUMERIC(5,0)( integer, integer)FLOAT(53)( integer)REALDOUBLEPRECISIONDEC...
syntaxsql CREATETYPE[schema_name. ]type_nameASTABLE( {<column_definition>[ , ...n ] } | [] [ , ...n ] | [] [ , ...n ] ) [WITH([ , ...n ] ) ] [ ; ]<column_definition>::=column_name<data_type>[COLLATEcollation_name] [NULL|NOTNULL] [IDENTITY[ (1,1) ] ] [<col...
Specifies whether to generate an error message when the last column in a row in the source file is lost during data loading. Value range: true, on, false, and off. The default value is false or off. If this parameter is set to true or on and the last column of a data row in a...
syntaxsql Copy CREATE TABLE { database_name.schema_name.table_name | schema_name.table_name | table_name } ( { <column_definition> | [ ] [ ,... n ] | [ ] [ ,... n ] } [ PERIOD FOR SYSTEM_TIME ( system_start_time_column_name , system_end_time_column_name ) ] ) ...
syntaxsql Copy CREATE TABLE { database_name.schema_name.table_name | schema_name.table_name | table_name } ( { <column_definition> | [ ] [ ,... n ] | [ ] [ ,... n ] } [ PERIOD FOR SYSTEM_TIME ( system_start_time_column_name , system_end_time_column_name ) ] ) ...
column_type Specifies the column type. definition Specifies a string constant defining a function. Its meaning depends on the language. It can be an internal function name, a path pointing to a target file, a SQL query, or text in a procedural language. ...
float 1 columns in index key Sparse column sets 1 The indexed view can contain float columns; however, such columns can't be included in the clustered index key. Important Indexed views aren't supported on top of temporal queries (queries that use FOR SYSTEM_TIME clause). Recommendations ...
语法:column_definition: col_name type [NOT NULL | NULL] [DEFAULT default_value] [AUTO_INCREMENT] [UNIQUE [KEY] | [PRIMARY] KEY] [COMMENT 'string'] [reference_definition] 举例: Create table tb(a int NOT NULL, b text PRIMARY KEY, c int AUTO_INCREMENT……)括号内的部分。在创建表定义列...