MySQL选择多个值？
要选择多个值，可以将where子句与OR和IN运算符一起使用。
语法如下-
情况1-使用OR
select *from yourTablename where yourColumnName = value1 or yourColumnName = value2 or yourColumnName = value3,.........N;
情况2-使用IN
select *from yourTableName where yourColumnName IN(value1,value2,....N);
为了理解上述语法，让我们创建一个表。以下是创建表的查询-
mysql> create table selectMultipleValues −> ( −> BookId int, −> BookName varchar(200) −> );
现在，您可以借助insert命令在表中插入一些记录。插入记录的查询如下-
mysql> insert into selectMultipleValues values(100,'Introduction to C'); mysql> insert into selectMultipleValues values(101,'Introduction to C++'); mysql> insert into selectMultipleValues values(103,'Introduction to java'); mysql> insert into selectMultipleValues values(104,'Introduction to Python'); mysql> insert into selectMultipleValues values(105,'Introduction to C#'); mysql> insert into selectMultipleValues values(106,'C in Depth');
在select语句的帮助下显示表中的所有记录。查询如下-
mysql> select *from selectMultipleValues;
以下是输出-
+--------+------------------------+ | BookId | BookName | +--------+------------------------+ | 100 | Introduction to C | | 101 | Introduction to C++ | | 103 | Introduction to java | | 104 | Introduction to Python | | 105 | Introduction to C# | | 106 | C in Depth | +--------+------------------------+ 6 rows in set (0.00 sec)
以下是借助OR运算符选择多个值的查询。
情况1-使用OR运算符。
mysql> select *from selectMultipleValues where BookId = 104 or BookId = 106;
以下是输出-
+--------+------------------------+ | BookId | BookName | +--------+------------------------+ | 104 | Introduction to Python | | 106 | C in Depth | +--------+------------------------+ 2 rows in set (0.00 sec)
情况2-使用In运算符。
以下是借助IN运算符选择多个值的查询。
mysql> select *from selectMultipleValues where BookId in(104,106);
以下是输出-
+--------+------------------------+ | BookId | BookName | +--------+------------------------+ | 104 | Introduction to Python | | 106 | C in Depth | +--------+------------------------+ 2 rows in set (0.00 sec)