INSERT mytable VALUES ('Dan'); 通过优化锁定,仅当实例中至少有一个使用 RangeI-N 隔离级别的事务时,才会获取 SERIALIZABLE 锁。 RangeI-N 模式键范围锁放置在与名称 David 对应的索引行上,以测试范围。 如果已授权锁,则插入包含值 Dan 的行,并将排他 (X) 锁放置在插入的行上。 RangeI-N 模...
values in the imported data file are to be used for the identity column. IfKEEPIDENTITYisn't specified, the identity values for this column are verified but not imported, and the query optimizer automatically assigns unique values based on the seed and increment values specified during table ...
例如,语句INSERT dbo.MyTable (Col1, Col2) VALUES (1, 10)可在内部实现为INSERT dbo.MyTable (Col1, Col2) VALUES (@p1, @p2)。 此过程称为“简单参数化”,它增强了关系引擎将新 SQL 语句与先前编译的现有执行计划进行匹配的能力。 由于减少了查询编译和重新编译的频率,因此可提高查询性能。 查询优化...
Each row in a table can have different values for columns that are involved in a computed column; therefore, the computed column might not have the same value for each row. Based on the expressions that are used, the nullability of computed columns is determined automatically by the Database...
The version of SQL Server with which the database is to be made compatible. The following compatibility level values can be configured (not all versions supports all of the above listed compatibility level): ProductDatabase Engine versionDefault compatibility level designationSupported compatibility level...
To validate that a value is valid in another table, use a foreign key constraint. To validate that a value in a column is within a specific range, use a check constraint. These objects are your first line of defense and are designed to work efficiently. For more informa...
Array data type in SQL server Array's IN SQL SERVER? ASCII values for extended characters Assign empty string '' if datetime is null Assign EXEC output to Variable Assigning NULL value to column name using Case Statement of where is SQL SERVER 2008 atomic if not exists() and insert or upd...
table lists the SQLSTATE values typically returned bySQLTablesand explains each one in the context of this function; the notation "(DM)" precedes the descriptions of SQLSTATEs returned by the Driver Manager. The return code associated with each SQLSTATE value is SQL_ERROR, unless noted ...
An error is not returned to the caller. When a RETURN statement is not used within an SQL procedure or when no value is specified: If a RETURN statement was not used to return from a procedure or if a value is not specified on the RETURN statement, one of the following values is set...
SQL (MS Access) to return values in table similar (to a set % tolerance) to values in another table. 1 Thread starter NWildblood Start date Apr 7, 2014 Not open for further replies. Apr 7, 2014 #1 NWildblood Technical User Nov 12, 2007 113 GB Hi I have 2 tables with ...