-- 创建存储过程CREATEPROCEDUREcount_char_occurrences(INinput_stringVARCHAR(255),INtarget_charCHAR(1))BEGINDECLAREcountINT;SETcount=0;DECLAREiINTDEFAULT1;WHILEi<=LENGTH(input_string)DOIFSUBSTRING(input_string,i,1)=target_charTHENSETcount=count+1;ENDIF;SETi=i+1;ENDWHILE;SELECTcount;END 1. 2. ...
Returns the substring from string str before count occurrences of the delimiter delim. If count is positive, everything to the left of the final delimiter (counting from the left) is returned. If count is negative, everything to the right of the final delimiter (counting from the right) is...
5. use intrepid_detectives; // 开始使用新创的那个数据库 database stores their data in tables.数据库将数据保存在table中,一个database可以有多张表,就像一个execel spreadsheet可以有多个sheet一样的概念。 6. show tables; mysql>useintrepid_detectives;Databasechanged mysql>show tables; Emptyset(0.00sec)...
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...
COUNTReturns the number of records returned by a select query DEGREESConverts a value in radians to degrees DIVUsed for integer division EXPReturns e raised to the power of a specified number FLOORReturns the largest integer value that is <= to a number ...
1 row in set (0.00 sec) Apart from SUSBTRING function MySQL also provides SUBSTRING_INDEX function which returns words occurring between delimiter SUBSTRING_INDEX Syntax SUBSTRING_INDEX(str,delim,count) Returns the substring from stringstrbeforecountoccurrences of the delimiterdelim. Ifcountis positive...
QUOTE() Escape the argument for use in an SQL statement REGEXP Pattern matching using regular expressions REPEAT() Repeat a string the specified number of times REPLACE() Replace occurrences of a specified string REVERSE() Reverse the characters in a string RIGHT() Return the specified rightmost...
Name Description BIT_COUNT() Return the number of bits that are set & Bitwise AND ~ Bitwise inversion | Bitwise OR ^ Bitwise XOR << Left shift Right shift Cast Functions and Operators Name Description BINARY Cast a string to a binary string CAST() Cast a value as a certain type CONVERT...
POSITION Returns the position of the first occurrence of a substring in a string REPEAT Repeats a string as many times as specified REPLACE Replaces all occurrences of a substring within a string, with a new substring REVERSE Reverses a string and returns the result RIGHT Extracts a number of...
--run-time-mode=s Set what the value of --run-time operates on ( default clock) --sample=i Filter out all but the first N occurrences of each query --set-vars=A Set the MySQL variables in this comma-separated list of variable=value pairs --show-all=H Show all values for these ...