DROP DATABASE database_name; In the above query, -database_name - is the name of the database to be dropped DROP DATABASE Example: If you want to drop database MyDatabase, the statement would be like DROP DATAB
The DROP command removes all the objects stored in the database and database from the SQL server. The DROP query removes the database permanently from the SQL Server. If tables and views stored in the database are important for you, then the data backup needs to be kept in another datab...
Query OK,1row affected (0.00sec) mysql>mysql>DROPDATABASEIFEXISTSA2;#删除一个库如果你不确定该库是否存在时,你可以使用判断语句,既然改库不存在你也不怕报错啦～Query OK,1row affected (0.01sec) mysql>mysql>SHOW DATABASES;+---+|Database|+---+|A3||course||day03||devops||information_schema|...
1 DROP DATABASE db_test; Drop Table 该语句用于删除表(table) 语法: Plain Text 复制 1 DROP TABLE [IF EXISTS] [db_name.]table_name; 举例: 1.删除一个 table Plain Text 复制 1 DROP TABLE my_table; 2.如果存在,删除指定 database 的 table Plain Text 复制 1 DROP TABLE IF EXISTS examp...
DROP TABLE Student; This query drops/deletes the entire Database School. 1 DROP DATABASE School; TRUNCATE The SQL TRUNCATE command is used to delete all the records/rows from the table without affecting the schema and structure of the database. The TRUNCATE Command is a Data Definition Langua...
DROP QUERY Test.BonusCalc FROM Employees.queryBonusCalc:drops the query Employees.BonusCalc(). 如果指定的查询不存在,DROP QUERY将生成SQLCODE-362错误。如果指定的类不存在,DROP QUERY将生成SQLCODE-360错误。如果指定的查询可以引用两个或多个查询,DROP QUERY将生成SQLCODE-361错误;必须指定一个类名来解决此歧义...
Dropping a database snapshot clears the plan cache for the instance of SQL Server. Clearing the plan cache causes a recompilation of all subsequent execution plans and can cause a sudden, temporary decrease in query performance. For each cleared cachestore in the plan cache, the SQL Server ...
sql:结构化查询语言(structed query language) 1.创建一个数据库 CREATEDATABASEmy_data_base; 2.使用刚刚创建的库 USEmy_data_base; 3.创建一个名为teacher的表格 CREATETABLEteacher ( nameVARCHAR(10), ageINT, birthday DATE ); 3.1.可以检查下创建的表 ...
<database_mirroring_option>|<date_correlation_optimization_option>|<db_encryption_option>|<db_state_option>|<db_update_option>|<db_user_access_option>|<delayed_durability_option>|<external_access_option>|<FILESTREAM_options>|<HADR_options>|<parameterization_option>|<query_store_options>|<recove...
DQL(Data Query Language):数据查询语言,用来查询记录(数据)。 一、DDL 查看所有数据库名称:SHOW DATABASES; 切换数据库:USE mydb1,切换到mydb1数据库; 查看当前使用的数据库的名称: select database(); #显示所有的数据库 SHOW DATABASES; #使用那个数据库 ...