sql server语法大全（SQL Server grammar Daquan）.docVIP

sql server语法大全（SQL Server grammar Daquan） date function DAY () -- returns the date value in date_expression MONTH () -- the function returns the month value in date_expression YEAR () - returns the year value in date_expression DATEADD (datepart, number, date) -- the function returns the new date created by the specified date date plus the specified additional date interval number DATEDIFF (datepart, number, date) -- the function returns the difference between the two specified dates in the datepart DATENAME (datepart, date) -- the function returns the specified part of the date in string DATEPART (datepart, date) -- the function returns the specified part of the date in the form of integer values GETDATE () -- the function returns the current date and time of the system in the default format of DATETIME system functions APP_NAME () -- the function returns the name of the application that is currently executing COALESCE () -- the function returns the value of the first non NULL expression in many expressions COL_LENGTH (table_name, column_name) -- the function returns the length value of the specified field in the table COL_NAME (table_id, column_id) -- the function returns the name of the specified field in the table, that is, column names DATALENGTH () -- the function returns the actual length of the data of the data expression DB_ID ([database_name]) -- the function returns the number of the database DB_NAME (database_id) -- the function returns the name of the database HOST_ID () -- the function returns the name of the server computer HOST_NAME () -- the function returns the name of the server computer IDENTITY (data_type[, seed, increment]) [AS column_name]) The --IDENTITY () function is used only in the SELECT INTO statement for inserting a identity column column into the new table /*select, identity (int, 1, 1) as, column_name Into newtable From oldtable*/ ISDATE () -- the function determines whether the given expression is a reasonable date ISNULL (check