这里假设我们使用一个简单的映射关系来获取表名,代码如下: Map<String,String>tableMappings=newHashMap<>();tableMappings.put("users","user_table");tableMappings.put("orders","order_table");StringtableName=tableMappings.get(tableNameVariable); 1. 2. 3. 4. 5. 在这段代码中,我们使用了一个HashMap...
USE[master]GOCREATEDATABASE[SQLTestDB]GOUSE[SQLTestDB]GOCREATETABLESQLTest (IDINTNOTNULLPRIMARYKEY, c1VARCHAR(100)NOTNULL, dt1 DATETIMENOTNULLDEFAULTgetdate() ); GOUSE[SQLTestDB]GOINSERTINTOSQLTest (ID, c1)VALUES(1,'test1')INSERTINTOSQLTest (ID, c1)VALUES(2,'test2')INSERTINTOSQLTest (...
DECLARE @mytablevariable my_type;。 B. 场景:替换全局 tempdb ##table 将全局临时表替换为内存优化的 SCHEMA_ONLY 表非常简单。 最大的改变是在部署时(而不是运行时)创建该表。 由于采用了编译时优化,创建内存优化表会比创建传统表所用时间更长。 创建和删除联机工作负载中的...
8 dbms_output.put_line('variable datatype length is small'); 9 end; 10 / Enter value for eno: 7788 old 4: select ename into v_ename from emp where empno=&eno; new 4: select ename into v_ename from emp where empno=7788; variable datatype length is small PL/SQL procedure successful...
SQLRETURN SQLTables( SQLHSTMT StatementHandle, SQLCHAR * CatalogName, SQLSMALLINT NameLength1, SQLCHAR * SchemaName, SQLSMALLINT NameLength2, SQLCHAR * TableName, SQLSMALLINT NameLength3, SQLCHAR * TableType, SQLSMALLINT NameLength4); 参数...
Temporary Tables And Table Variables In SQL 基本常识 1. 局部临时表(#开头)只对当前连接有效,当前连接断开时自动删除 2. 全局临时表(##开头)对其它连接也有效,在当前连接和其他访问过它的连接都断开时自动删除 3. 临时表就像普通表一样,它可以做索引等等 ...
SELECT *, 0, GETDATE() FROM @TVP; GO /*声明一个变量来引用该类型*/ DECLARE @LocationTVP AS LocationTableType; /* Add data to the table variable. */ INSERT INTO @LocationTVP (LocationName, CostRate) SELECT [Name], 0.00 FROM
DELTA_CREATE_EXTERNAL_TABLE_WITHOUT_SCHEMA、DELTA_CREATE_TABLE_MISSING_TABLE_NAME_OR_LOCATION、DELTA_CREATE_TABLE_WITH_NON_EMPTY_LOCATION、DELTA_DUPLICATE_DOMAIN_METADATA_INTERNAL_ERROR、DELTA_FAILED_RECOGNIZE_PREDICATE、DELTA_IDENTITY_COLUMNS_PARTITION_NOT_SUPPORTED、DELTA_ILLEGAL_USAGE、DELTA_MERGE_MISSING...
('t_contents_',@tbl,''); SET @GetName = CONCAT(' SELECT GROUP_CONCAT(DISTINCT CONCAT ( "max(IF(`pname` = '",pname,'\',contents,NULL)) AS `', pname, '`') ) INTO @sql FROM `', tablename, '`;'); SELECT @GetName; PREPARE stmt FROM @GetName; EXECUTE stmt; DEALLOCATE ...
1 This definition of session variable is specific to this context, as part of non-deterministic-expression. column-alteration: column-name SETDATA TYPEaltered-data-typeINLINE LENGTHinteger1SETdefault-clauseSETINLINE LENGTHintegerSETGENERATEDALWAYSBY DEFAULTidentity-alterationidentity-alterationSETGENERATEDALWAYS...