表的关系: Cardgraderule 1:n Cardgrade Cardgrade 1:n Acardtype 实体类: public class Cardgraderule implements java.io.Serializable { private Cardgrade cardgrade; ...... } public class Cardgrade implements java.io.Serializable { private
情景: student id stname sex score scoreid stname birth course id coursename age 简单说明 a,b ,c 三表a.name=b.name a.id=c.id 现在要查 id ,name ,course 有两种方法: select a.id,b.name,c. coursename from student a,score b,course c where a.name=b.name and
var result = 0; var userId = 0; using (var db = _Sql.Connection) using (var tran =db.BeginTransaction()) { var insertUserActionSql = @"INSERT INTO [dbo].[Base_User] ([UserName] ,[Password] ,[PhoneNumber] ,[Email] ,[IsDeleted] ,[CreateDate] ,[CreateUs
ORACLE: 1.查主键名称: select * from user_constraints where table_name = 'AAA' and constraint_type ='P'; 查主键对应的列: select * from user_cons_columns where table_name = 'AAA' and constraint_name = 'PK_AAA'; (PK_AAA 是主键名) 2.查索引名称: select * from user_indexes whe