mysql if

MySQL can be used as an expression, or as a Process control statement in a stored procedure, as an expression:An If expressionIF(expr1,expr2,expr3)If Expr1 is true (expr1 <> 0 and Expr1 <> NULL), then the return value of if () is expr2; Otherwise

Public Static stringRetunsql (stringSstringe) { return @"IF ("+s+">"+e+@", DATEDIFF ("+ E +@", "+ S +@")-Floor (ABS (DATEDIFF (Subdate ( "+ E +@", Date_format ("+ E +@", '%w ')-1),"+ S +@")/7 * 1)) * 2 *-1, DATE DIFF ("+ E +@",

CREATE PROCEDURE userinfo_modify (in ID int,in loginid int,in levelid Int,innamestrvarchar (+), Intelvarchar (50), Inaccountvarchar ()) Beginset @lid =loginid;set @lvid =levelid;set @n=namestr;set @t=tel;set @a=account;set @uid =id; Select @eid

Case has two formats. Simple case function and case search function.--Simple case function when ' 1 ' then ' Male ' when ' 2 ' Then ' Women ' Else ' other ' end--case search function case when sex = ' 1 ' Then ' Man ' when sex = ' 2 '

usage of if: MySQL> Select if(Ten>9,Ten,9) asBigger fromdual;+--------+|Bigger|+--------+| Ten |+--------+ Leftusage of () and Right (): MySQL> Select Left('Abcdeft',4A Right('Abcdeft',4) b;+------+------+|A|B|+------+------+|Abcd|Deft|+------+-

A friend of mine suddenly sent me a SQL statement and asked me all at once.I think this kind of grammatical wood has been seen. I checked, only to understand what the meaning of the original is the use of MySQL inside.SUM (IF (' hosts ') (state = 0,

We know that the database storage money type can be float, double, decimal, compared to decimal is the best use.Well, our company is divided into units, type with bigint access, operation of the time to is very convenient, when the show will have to

We can see the log today. I don't know why, since last week. mysql eats 50% CPU of my server. however, I shut down all mysql programs. mysql CPU consumption is still high. no exception is found in the slow query. We can see the log today. I don't

Import data with a. sql file, and if you import the Table1 table, the table table1 exists first ALTER table How do I write this SQL? Thank you Reply to discussion (solution) What's the name of the table?Change a table that already exists? So

1. Scene OneSometimes query number a simultaneously query filtered quantity b2. CodeSELECT count (id) as Total_count, count ( IF ( = DATE (now) ), 1, NULL ) ) As Today_countfrom =

If it does not exist, insert the new data $sql = "INSERT into {$ecs->table (' Cat_lang ')} (CAT_ID,LANG_ID,CAT_NAME,KEYWORDS,CAT_DESC) VALUES ({$cat _id},{$k}, ' {$val [' cat_name ']} ', ' {$val [' keywords ']} ', ' {$val [' Cat_desc ']} '} ') On

insert into Invite_rejectlog_num (player_id,month,count,last_modify_ Time) VALUES (#{playerid},#{month},#{count},#{lastmodifytime}) on DUPLICATE KEY UPDATE count=count+1;Unique constraint ID and month requiredAva Month calculation comparisonCalendar

If you are new to the MySQL database, you will certainly have some difficulties in learning it. The following articles are mainly for new users, that is, the prelude to using MySQL, if you are interested in the content related to the prelude used by

at night a small study of the next MySQL stored in the Read binary data function. The key step is the following three points: the most important point: the type of table that stores the binary data needs to be a blob type (divided by length tiny,

Download the mysql-5.5.19-linux2.6-i686.tar.gz package from the official network. Decompress this package and use it as a compiled file. You can directly modify the configuration without compiling or installing it yourself. Objective-C Download the

RedHat version: 6.2 Mysql version: mysql-5.5.19 Installation Package file name: mysql-5.5.19-linux2.6-x86_64.tar.gz 1. installation steps: Download the mysql-5.5.19-linux2.6-i686.tar.gz package from the official network. Decompress this package and

RedHat version: 6.2mysql version: mysql-5.5.19 installation package file name: mysql-5.5.19-linux2.6-x86_64.tar.gz 1, installation steps: on the official website RedHat version: 6.2 mysql version: mysql-5.5.19 installation package file name: mysql-5.

First, the System review:This system is a simple student management system, and the former do a student management system from the functional mountain, in fact, is the same. The difference is that the underlying storage part of the previous student

DROPPRIMAYDEY is used to cancel the primary index. Note: in earlier versions of MySQL, if there is no primary index, DROPPRIMARYKEY will cancel the first UNIQUE index in the table. This does not happen in MySQL5.1. If you use dr drop primay dey to

Explanation of the usage of explain in mysql MySQLexplain BitsCN.com The explanation of mysql explain is clear.Of With the help of explain, you will know when to add an index to the table to use the index to search for records so that select can run