Mapper interface files in MyBatis and instance functions of the example class and detailed

# #Example Example =New# #Example (); Example.setorderbyclause ("Field name ASC");//in ascending order, DESC is in descending order. Example.setdistinct (false)//Remove Duplicates, Boolean, True to select records that are not duplicates. Criteria =NewExample (). Createcriteria (); isNULL; is notNULL;    Equal to (value); n equal to (value); GreaterThan (value);    Greaterthanorequalto (value); LessThan (value);    Lessthanorequalto (value); In (Item,item,item,...);    Not in (Item,item,item,...); Like ("%" +value+ "%"); not-like ("%" +value+ "%"); Between (value1,value2); mybatis instance function in not between (value1,value2) Mapper:intCountbyexample (userexample example) Thorws SQLException: Count by condition. intDeletebyprimarykey (Integer ID) thorws SQLException: Delete by primary key. intDeletebyexample (userexample example) Thorws SQLException: Delete by condition. String/integer insert (user record) Thorws SQLException: Insert (return value is ID value) User selectbyprimarykey (integer ID) thorws SQLException    : Press primary key to query. List<?>Selectbyexample (userexample example) THORWS SQLException: Query List by Criteria<?>Selectbyexamplewithblogs (userexample example) THORWS SQLException: Query by criteria (including BLOB fields).    Only if the field type in the data table is binary is it generated. intUpdatebyprimarykey (User record) Thorws SQLException: Update by primary keyintupdatebyprimarykeyselective (User record) Thorws SQLException: Update A field with a value that is not NULL by the primary keyintupdatebyexample (User record, userexample example) THORWS SQLException: Update by conditionintupdatebyexampleselective (User record, userexample example) THORWS SQLException: Update A field with a value that is not NULL by condition Mybati Example function of mapper in S: ①selectbyprimarykey () User User= # #Mapper. Selectbyprimarykey (100); Equivalent to select *From user where ID= 100②selectbyexample () and Selectbyexamplewithblogs () userexample Example=Newuserexample (); Criteria Criteria=Example.createcriteria (); Criteria.andusernameequalto ("Joe");    Criteria.andusernameisnull (); Example.setorderbyclause ("Username Asc,email desc"); List<?>list =# #Mapper. Selectbyexample (example); Equivalent to: Select* FROM user where username = ' Joe ' and username areNULLORDER BY username Asc,email desc Note: The ibator generated file Userexample.java contains a static internal class Criteria, in Crit        There are many methods in Eria, mainly defining the query condition after the SQL statement where. ③insert () User User=NewUser (); User.setid (101); User.setusername ("Test"); User.setpassword ("123") User.setemail ("[Email protected]");    # #Mapper. Insert (user); Equivalent to: INSERT INTO user (Id,username,password,email) VALUES (101, ' Test ', ' 123 ', ' [email protected] '); ④updatebyprimarykey () and updatebyprimarykeyselective () user User=NewUser (); User.setid (101); User.setusername ("Joe"); User.setpassword ("Joe"); User.setemail ("[Email protected]");    # #Mapper. Updatebyprimarykey (user); Equivalent to: Update user set username= ' Joe ', password= ' Joe ', email= ' [email protected] 'where ID=101User User=NewUser (); User.setid (101); User.setpassword ("Joe");    # #Mapper. updatebyprimarykeyselective (user); Equivalent to: Update user set Password= ' Joe ' where id=101⑤updatebyexample () and updatebyexampleselective () userexample Example=Newuserexample (); Criteria Criteria=Example.createcriteria (); Criteria.andusernameequalto ("Joe"); User User=NewUser (); User.setpassword ("123");    # #Mapper. updatebyprimarykeyselective (User,example); Equivalent to: Update user set Password= ' 123 ' where username= ' Joe '⑥deletebyprimarykey () # #Mapper. Deletebyprimarykey (101); Equivalent to: Delete from user where id=101⑦deletebyexample () userexample Example=Newuserexample (); Criteria Criteria=Example.createcriteria (); Criteria.andusernameequalto ("Joe");    # #Mapper. Deletebyexample (example); Equivalent to: Delete from user where username= ' Joe '⑧countbyexample () userexample Example=Newuserexample (); Criteria Criteria=Example.createcriteria (); Criteria.andusernameequalto ("Joe"); intCount =# #Mapper. Countbyexample (example); Equivalent to: SELECT COUNT (*) from user where username= ' Joe '

Mapper interface files in MyBatis and instance functions of the example class and detailed