DROP DATABASE DROP DATABASE database_name DROP INDEX DROP INDEX table_name.index_name (SQL Server)DROP INDEX index_name ON table_name (MS Access)DROP INDEX index_name (DB2/Oracle)ALTER TABLE table_nameDROP INDEX index_name (MySQL) DROP TABLE DROP TABLE table_name EXISTS IF EXISTS (SELECT...
How to use SQL in: MySQL, SQL Server, MS Access, Oracle, Sybase, Informix, Postgres, and other database systems.NumPyHow NumPy can be used for arrays in statistics and math.PandasHow Pandas can be used for data analysis.RHow to use R for managing different types of data. How to use...
SQL 是用于访问和处理数据库的标准的计算机语言。 在本教程中,您... MySQL 教程 MySQL是一个关系型数据库管理系统。 SQLite 教程 一款轻型的数据库。 MS Access 教程 Microsoft Access是来自Microsoft的数据库管... MongoDB 教程 Mongo DB 是目前在IT行业非常流行的一种非关系型数据库(N... ...
TheDROP INDEXcommand is used to delete an index in a table. MS Access: DROPINDEXindex_nameONtable_name; SQL Server: DROPINDEXtable_name.index_name; DB2/Oracle: DROPINDEXindex_name; MySQL: ALTERTABLEtable_name DROPINDEXindex_name; ❮ SQL Keywords Reference...
❮Previous❮ MS Access FunctionsNext❯ ExampleGet your own SQL Server Return the year part of the specified date: SELECTDatePart("yyyy", #09/05/2017#); Try it Yourself » Definition and Usage The DatePart() function returns a specified part of a date, as an integer. ...
❮ Previous ❮ MS Access Functions Next ❯ ExampleGet your own SQL Server Remove leading spaces from a string: SELECT LTrim(" SQL Tutorial") AS LeftTrimmedString; Try it Yourself » Definition and UsageThe LTrim() function removes leading spaces from a string....
SQL How to store, change and retrieve data in databases with SQL How to use SQL in: MySQL, SQL Server, MS Access, Oracle, Sybase, Informix, Postgres, and other database systems NumPy How NumPy can be used for arrays in statistics and math ...
SQL Server / Oracle / MS Access:ALTER TABLE Persons DROP CONSTRAINT CHK_PersonAge; MySQL:ALTER TABLE Persons DROP CHECK CHK_PersonAge; DROP DEFAULTThe DROP DEFAULT command is used to delete a DEFAULT constraint.To drop a DEFAULT constraint, use the following SQL:...
❮ Previous ❮ MS Access Functions Next ❯ ExampleGet your own SQL Server Return the current system date: SELECT CustomerName, Date() AS CurrentDateFROM Customers; Try it Yourself » Definition and UsageThe Date() function returns the current system date....
MS Access:DROP INDEX index_name ON table_name; SQL Server:DROP INDEX table_name.index_name; DB2/Oracle:DROP INDEX index_name; MySQL:ALTER TABLE table_nameDROP INDEX index_name; ❮ SQL Keywords Reference Track your progress - it's free! Log in Sign Up ...