如果您直接查詢歷程記錄資料表,請確定篩選條件也是 SARG-able,方式是指定形式為 <period column> { < | > | =, ... } date_condition AT TIME ZONE 'UTC' 的篩選條件。如果您將 AT TIME ZONE 套用到期間資料行,SQL Server 將會執行資料表或索引掃描,這可能會耗費相當多的資源。 請在查詢中避免這類...
Simple CREATE TABLE syntax (common if not using options): syntaxsql Copy CREATE TABLE { database_name.schema_name.table_name | schema_name.table_name | table_name } ( { <column_definition> } [ ,... n ] ) [ ; ] Full syntax Disk-based CREATE TABLE syntax: syntaxsql Copy CREATE...
SQL Server does not care about the ordinal position. If you want to create the table with a specific column order or reaarange order, you will have to recreate the table and dump data out and in to the new table. Why do you care about the oridinal position, relying on this is not ...
[STR_LEN]; SQLCHAR szTableName[STR_LEN]; SQLCHAR szTypeName[STR_LEN]; SQLCHAR szRemarks[REM_LEN]; SQLCHAR szColumnDefault[STR_LEN]; SQLCHAR szIsNullable[STR_LEN]; SQLINTEGER ColumnSize; SQLINTEGER BufferLength; SQLINTEGER CharOctetLength; SQLINTEGER OrdinalPosition; SQLSMALLINT ...
Encrypt a column of data Secure Azure SQL Database Auditing Ledger Networking Concepts Tutorials Reference Tools Tutorials SQL Server on Linux SQL on Azure Azure Arc Resources Reference Download PDF Save Add to Collections Add to plan Share via ...
Changed column names in system objects. In SQL Server 2012 (11.x) the columnsingle_pages_kbinsys.dm_os_sys_infowas renamed topages_kb. Regardless of the compatibility level, the querySELECT single_pages_kb FROM sys.dm_os_sys_infowill produce error 207 (Invalid column name). ...
42S21Column already exists*StatementTextcontained anALTER TABLEstatement, and the column specified in theADDclause is not unique or identifies an existing column in the base table. 42S22Column not found*StatementTextcontained aCREATE INDEXstatement, and one or more of the column names specified in ...
You can add, drop, or modify the columns of an external table. However, for an external table you cannot: Add a LONG, LOB, or object type column or change the datatype of an external table column to any of these datatypes. Add a constraint to an external table. Modify the storage...
Syntax for ALTER TABLE ALTER TABLE table-name 1ADDCOLUMNcolumn-definitionALTERCOLUMNcolumn-alterationRENAME COLUMNsource-column-nameTOtarget-column-nameDROPCOLUMNcolumn-nameRESTRICTADD PERIODFORperiod-definitionADDunique-constraintreferential-constraintcheck-constraint4DROPRPRIMARY KEYUNIQUEFOREIGN KEYCHECKCONSTRAINT...
CREATE TABLE的列约束: 列约束中用REFERENCES REFERENCES reftable [ ( refcolumn ) ] reftable [ ( refcolumn ) ] [ MATCH FULL | MATCH PARTIAL | [ MATCH FULL | MATCH MATCH SIMPLE ] [ ON DELETE PARTIAL | MATCH action ] [ ON UPDATE action ] SIMPLE ] [ ON DELETE ...