sql where multiple conditions

Recently, the company is working on the Wuhan public transport information management system. The most painful thing for such management projects is the addition, modification, and query of forms. Add or modify Article As mentioned in, the reflection mechanism can be used to do nothing. Code . See Automatic Data Binding and modification in the ORM framework The above only solves the problem of adding, modifying, and displaying the list. However, when querying

// Name field corresponding to textbox1// The password field corresponding to textbox2Using system;Using system. Collections. Generic;Using system. componentmodel;Using system. Data;Using system. drawing;Using system. text;Using system. Windows. forms;Using system. Data. sqlclient; Namespace findrow{Public partial class form1: Form{String SQL;Public form1 (){Initializecomponent ();} Private void button#click (Object sender, eventargs E){If (textbox1.t

' other ' ENDFrom Table_aGROUP by Case CountryWhen ' China ' then ' Asia 'When ' India ' Then ' Asia 'When ' Japan ' then ' Asia 'When ' America ' Then ' North America 'When ' Canada ' then ' North America 'When ' Mexico ' then ' North America 'Else ' other ' END;Similarly, we can use this method to judge the salary level, and to count the number of each level. The SQL code is as follows;SELECTCase when salary When salary > Salary When salary > Salar

Table structureTag table:{tag_id, tag_name} #标签表News table:{news_id, Title,......} #新闻表Newstags table:{tag_id, news_id} #新闻的标签关系表Explain:A piece of news that has multiple tag tags, such as:News A{tag1,tag2, TAG3, TAG4}News B{tag1,tag6, Tag7, Tag8}News C{tag8,tag9, TAG10, TAG1}News... {Tag ..., ...}Search for records with TAG1,TAG8 two tags at the same time.SQL optimized in MySQL:Select News.titlefrom ( select news_id from ( select tag_id from

SQL statement The code is as follows Copy Code SELECT * FROM _test a LEFT join _test B on a.id=b.id where a.level= ' and a.month= ' and b.level= ' 03 ' ;Select a.*,b.* from (SELECT * to _test where level= ' and month= ') as a LEFT join (SELECT * from _test where level= ' ' and month= ') as B on a.id=b.id; The results of these two statements are different and should be left join when the condition is that

Recently has been doing data statistics, in the process, encountered a good many situations are a table according to different conditions for multiple statistics, the previous practice is to count several times according to different conditions left join several times, although also can get the desired results, but the efficiency is too low, reflected in the page

When querying data, people often need to set query conditions. In SQL or HQL statements, query conditions are often placed in the WHERE clause. In addition, hibernate supports the criteria query, which encapsulates the query criteria as a criteria object. In practical applications, the Createcriteria () method of the session is used to construct a Org.hibernate.C

Related queries for multiple Laravel conditions About the Association query of multiple Laravel conditions: TableorderOrder table: idAuto-increment ID order_idOrder No. paid_datePayment time Tableorder_productOrder product table: idAuto-increment ID fk_order_idOrder Number, foreign key product_nameName prod

Previously, I encountered a technical problem with the query of a complicated Linq to EF. The Product name of the existing Product table needs to be fuzzy matched Based on Multiple keywords. Now I will share the solution.Problem description As required, we need to write the following SQL statement to query the productCopy codeThe Code is as follows:Select * from dbo. ProductWhere(ProductName like 'product1%

Previously, I encountered a technical problem with the query of a complicated Linq to EF. The Product name of the existing Product table needs to be fuzzy matched Based on Multiple keywords. Now I will share the solution. Problem description As required, we need to write the following SQL statement to query the productCopy codeThe Code is as follows: select * from dbo. ProductWhere(ProductName like 'produc

Mysql compared to the problem of updating another table with multiple conditions A B C three tablesData TableB sets the BID B1 B2 B3 fields for the condition.C is the cid uid field of the user table.Table A meets the three conditions A1 A2 A3. these three conditions are the condit