@local_variable除cursor、text、ntext、image 或table 之外的任何类型的变量的名称。 变量名称必须以 at 符号 (@) 开头。 变量名称必须遵循有关标识符的规则。property_name用户定义类型的属性。field_name用户定义类型的公共字段。udt_name公共语言运行时 (CLR) 用户定义类型的名称。
SET@local_variable{ = | += | -= | *= | /= | %= | &= | ^= | |= } expression Arguments @local_variable The name of a variable of any type exceptcursor,text,ntext,image, ortable. Variable names must start with one at sign (@). Variable names must follow the rules foridentif...
AlterTableAlterColumnOption AlterTableAlterColumnStatement AlterTableAlterIndexStatement AlterTableAlterPartitionStatement AlterTableChangeTrackingModificationStatement AlterTableConstraintModificationStatement AlterTableDropTableElement AlterTableDropTableElementStatement AlterTableFileTableNamespaceStatement AlterTableRebuildState...
-- Private: The variable is available only in the current scope.-- AllScope: The variable is copied to any new scopes that are created.To see the Options property of all variables in the session, type "Get-Variable | Format-Table -property name, options -autosize"....
If the cursor is passed back in an OUTPUT parameter, the cursor is deallocated when the last variable that references it is deallocated or goes out of scope. GLOBAL When GLOBAL is specified, and a cursor is not defined as LOCAL when created, the scope of the cursor is global to the ...
the schema name of the base table that contains the column. The return value is driver-dependent if the column is an expression or if the column is part of a view. If the data source does not support schemas or the schema name cannot be determined, this variable contains an empty string...
我们首先从《MySQL 5.6 Reference Manual》的"CREATE INDEX"章节看起,他指出如果是字符串类型的字段,可以指定字符串前多少位创建索引键值,而且键值前缀是存在上限的,在CREATE TABLE、ALTER TABLE、CREATE INDEX语句中,对于非二进制的字符串类型(CHAR、VARCHAR、TEXT),前缀会按照字符个数计算,对二进制的字符串类型(BINAR...
alter table order_info add index idx_name(username) 1. 利用索引字段排序 索引总结 MySQL只对以下操作符才使用索引,<,<=,=,>=,between and,like 非%开头使用索引,in可能走索引可能不走,!=不走索引,理论上每张表可创建16个索引。 MySQL会对允许null列也加上索引,但只会对is null``的查询条件生效 ...
Typically, the items available in a variable set all exist on the same page of the catalog.A variable set item is designated by a V in the Kit type field in the Item table. A variable set, for example a Wardrobe Set, may be a special collection of items such as: “Choose any 2 ...
git-show-index(1) git-show-ref(1) git-show(1) git-stage(1) git-stash(1) git-status(1) git-stripspace(1) git-submodule(1) git-svn(1) git-symbolic-ref(1) git-tag(1) git-tar-tree(1) git-unpack-file(1) git-unpack-objects(1) git-update-index(1) git-update-ref(1) git-up...