UNION ALL SELECT column_name(s) FROM table_name2 UPDATE UPDATE table_name SET column1=value, column2=value,... WHERE some_column=some_value WHERE SELECT column_name(s) FROM table_name WHERE column_name operator valueSource : http://www.w3schools.com/sql/sql_quickref.asp«...
SELECT column_name(s) FROM table_name2 UPDATEUPDATE table_name SET column1=value, column2=value,... WHERE some_column=some_value WHERESELECT column_name(s) FROM table_name WHERE column_name operator value Source : https://www.w3schools.com/sql/sql_quickref.asp ...
CREATE TABLE SQLCREATE TABLE语句 SQL CREATE TABLE 语句 CREATE TABLE 语句用于在数据库中创建新表。 语法 CREATETABLEtable_name( column1 datatype, column2 datatype, column3 datatype, ... ); column1 参数指定表中列的名称。 datatype 参数指定列可以保存的数据类型(例如varchar、integer、date等)。
DELETE - 从数据库中删除数据 INSERT INTO - 向数据库中插入新数据 CREATE DATABASE - 创建新数据库 ALTER DATABASE - 修改数据库 CREATE TABLE - 创建新表 ALTER TABLE - 变更(改变)数据库表 DROP TABLE - 删除表 CREATE INDEX - 创建索引(搜索键) DROP INDEX - 删除索引 ❮...
CREATE DATABASE CREATE DATABASE database_name CREATE TABLE CREATE TABLE table_name(column_name1 data_type,column_name2 data_type,column_name3 data_type,...) CREATE INDEX CREATE INDEX index_nameON table_name (column_name) or CREATE UNIQUE INDEX index_nameON table_name (column_name) CREATE...
Exercise: SQL Create TableWhat is the primary purpose of the SQL CREATE TABLE statement?To create a new table in a database To insert data into a table To join a table To delete a table from a databaseSubmit Answer » What is an Exercise? Test what you learned in the chapter: ...
« W3Schools Home Next Chapter » SQL SQL is a standard language for accessing databases. Our SQL tutorial will teach you how to use SQL to access and manipulate data in: MySQL, SQL Server, Access, Oracle, Sybase, DB2, and other database systems....
You answered: True Correct Answer! 24. Which operator is used to search for a specified pattern in a column? You answered: LIKE Correct Answer! 25. Which SQL statement is used to create a table in a database? You answered: CREATE TABLE Correct Answer!分类...
通过创建联合索引,可以提高查询效率,加快数据检索的速度。在创建联合索引时,需要注意索引字段的顺序,并根据实际情况选择合适的字段创建索引。合理地使用联合索引可以让数据库系统更高效地处理查询操作。 参考资料 MySQL Documentation: [Indexes]( W3Schools MySQL Tutorial: [MySQL Indexes](...
我正在做一个学习 SQL 的小组项目,我现在和 w3schools 使用 jdoodle 作为在线 IDE。我问这个问题感到很奇怪,因为这实际上是我的第一次尝试,但我收到了错误。 CREATE DATABASE turing; CREATE TABLE Suppliers ( SupplierNumber int, SupplierName varchar(255), SupplierAddress varchar(255), ); Error: near ...