实现分割字符串。 DELIMITER $$ CREATE DEFINER=`root`@`%` FUNCTION `func_get_split_string_total`( f_string VARCHAR(1000),f_delimiter VARCHAR(5) ) RETURNS INT(11) BEGIN -- Get the total number of given string. RETURN 1+(LENGTH(f_string) - LENG
实现分割字符串。DELIMITER $$ CREATE DEFINER=`root`@`%` FUNCTION `func_get_split_string_total`( f_string VARCHAR(1000),f_delimiter VARCHAR(5) ) RETURNS INT(11) BEGIN -- Get the total number of given string. RETURN 1+(LENGTH(f_string) - LENGTH(REPLACE(f_string,f_delimiter,''))); END$$ DELIMITER ;
DELIMITER $$ CREATE DEFINER=`root`@`%` FUNCTION `func_get_split_string`( f_string VARCHAR(1000),f_delimiter VARCHAR(5),f_order INT) RETURNS VARCHAR(255) CHARSET utf8 BEGIN -- Get the separated number of given string. DECLARE result VARCHAR(255) DEFAULT ''; SET result = REVERSE(SUBSTRING_INDEX(REVERSE(SUBSTRING_INDEX(f_string,f_delimiter,f_order)),f_delimiter,1)); RETURN result; END$$ DELIMITER ;
DELIMITER $$ CREATE PROCEDURE `sp_print_result`( IN f_string VARCHAR(1000),IN f_delimiter VARCHAR(5) ) BEGIN -- Get the separated string. DECLARE cnt INT DEFAULT 0; DECLARE i INT DEFAULT 0; SET cnt = func_get_split_string_total(f_string,f_delimiter); DROP TABLE IF EXISTS tmp_print; CREATE TEMPORARY TABLE tmp_print (v_text varchar(200) NOT NULL); WHILE i <pre class="brush:php;toolbar:false"> 我们来执行:
CALL sp_print_result('love,you,hate,number',','); query result v_text love you hate numbercreate or replace function split_to_string( IN f_string text, IN f_delimiter varchar(10) ) returns setof text as $ytt$ declare cnt int; declare i int; declare v_result text; begin i := 1; cnt := length(f_string) - length(replace(f_string,f_delimiter,''))+1; while i t_girl=# SELECT ytt FROM regexp_split_to_table('love,you,hate,number', E',+') AS ytt; ytt -------- love you hate number (4 rows) t_girl=#
第三种,用自带的WITH 语法来实现。
t_girl=# with recursive ytt(f1,f2) as ( values (0,' '::text) union all select f1+1,split_part('love,you,hate,number',',',f1+1) from ytt where f1 < 20 ) select f2 as result from ytt where f1 >=1 and f1 <= length('love,you,hate,number')-length(replace('love,you,hate,number',',',''))+1; result -------- love you hate number (4 rows) Time: 0.742 ms

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Adding MySQL users through the PHP web interface can use MySQLi extensions. The steps are as follows: 1. Connect to the MySQL database and use the MySQLi extension. 2. Create a user, use the CREATEUSER statement, and use the PASSWORD() function to encrypt the password. 3. Prevent SQL injection and use the mysqli_real_escape_string() function to process user input. 4. Assign permissions to new users and use the GRANT statement.

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ToaddauserinMySQL,use:CREATEUSER'username'@'host'IDENTIFIEDBY'password';Here'showtodoitsecurely:1)Choosethehostcarefullytocontrolaccess.2)SetresourcelimitswithoptionslikeMAX_QUERIES_PER_HOUR.3)Usestrong,uniquepasswords.4)EnforceSSL/TLSconnectionswith

ToavoidcommonmistakeswithstringdatatypesinMySQL,understandstringtypenuances,choosetherighttype,andmanageencodingandcollationsettingseffectively.1)UseCHARforfixed-lengthstrings,VARCHARforvariable-length,andTEXT/BLOBforlargerdata.2)Setcorrectcharacters


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