The first syntax returns the position of the first occurrence of substring substr in string str. The second syntax returns the position of the first occurrence of substring substr in string str, starting at position pos. Returns 0 if substr is not in str. Returns NULL if substr or str is ...
LOCATE() Return the position of the first occurrence of substring LOWER() Return the argument in lowercase LPAD() Return the string argument, left-padded with the specified string LTRIM() Remove leading spaces MAKE_SET() Return a set of comma-separated strings that have the corresponding bit ...
要将操作数作为DATETIME值进行比较,请使用CAST()将子查询值显式转换为DATETIME。 如果其中一个参数是十进制值,则比较取决于另一个参数。如果另一个参数是十进制或整数值,则将参数作为十进制值进行比较,如果另一个参数是浮点值,则将参数作为浮点值进行比较。 在所有其他情况下,参数将作为浮点(双精度)数进行比较。...
9.FIND_IN_SET FIND_IN_SET(str,strlist) 如果字符串str在由N子串组成的表strlist之中,返回一个1到N的值。一个字符串表是被“,”分隔的子串组成的一个字符串。如果第一个参数是一个常数字符串并且第二个参数是一种类型为SET的列,FIND_IN_SET()函数被优化而使用位运算!如果str不是在strlist里面或如果st...
或create table test(id int) character set utf8 collate utf8_bin; 或alter table test modify id collate utf8_bin; 3.7 (m)Mysql 不可使用动态表名 解决:只能使用写死操作,不可使用动态入参 如创建函数不可使用入参: CREATE FUNCTION SPECIAL_DATE(TODAY VARCHAR(255) , TBALE_NAME VARCHAR(255) ,CO...
private final String USERNAME = "test"; private final String PASSWORD = "123456"; private final String DRIVER = "com.mysql.jdbc.Driver"; private final String URL = "jdbc:mysql://10.10.10.10:3306?userunicode=true&characterEncoding=utf8mb4"; private Connection connection; private PreparedStatement...
四种联接 left join(左联接)返回包括左表中的所有记录和右表中联结字段相等的记录 right join(右...
() Return the position of the first occurrence of substring LOWER() Return the argument in lowercase LPAD() Return the string argument, left-padded with the specified string LTRIM() Remove leading spaces MAKE_SET() Return a set of comma-separated strings that have the corresponding bit in ...
LCASE Converts a string to lower-case LEFT Extracts a number of characters from a string (starting from left) LENGTH Returns the length of a string (in bytes) LOCATE Returns the position of the first occurrence of a substring in a string LOWER Converts a string to lower-case LPAD Left-...
BIN_TO_UUID() Convert binary UUID to string BINARY Cast a string to a binary string Yes BIT_AND() Return bitwise AND BIT_COUNT() Return the number of bits that are set BIT_LENGTH() Return length of argument in bits BIT_OR() Return bitwise OR BIT_XOR() Return bitwise XOR ...