ShadowSql之极简模式查询示例

ShadowSql拼接sql可以很简单,非必须的事情都可以不做,非必须的对象也都不构造。
可以不用提前配置,开箱即用。
这里我们示例一下极简模式。
 
一、极简单表查询
1. SqlQuery极简查询

1.         var users = SimpleDB.From("Users");
2.         var query = users.ToSqlQuery()
3.             .Where(users.Field("Id").LessValue(100));

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我们还可以用这样查询

1.         var query = SimpleDB.From("Users")
2.             .ToSqlQuery()
3.             .Where(users => users.Field("Id").LessValue(100));

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sql: SELECT * FROM [Users]  WHERE [Id] users.Field("Id").LessValue(100));[/code]
sql: SELECT * FROM [Users]  WHERE [Id] t1.Field("DepartmentId").Equal(t2.Field("Id")))            .WhereLeft(t1 => t1.Field("Age").GreaterValue(30))            .WhereRight(t2 => t2.Field("Manager").EqualValue("CEO"));[/code]

1.         var users = SimpleDB.From("Users");
2.         var query = users.ToQuery()
3.             .And(users.Field("Id").LessValue(100));

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sql: SELECT * FROM [Employees] AS e INNER JOIN [Departments] AS d ON e.[DepartmentId]=d.[Id] WHERE e.[Age]>30 AND d.[Manager]='CEO'

1.         var query = SimpleDB.From("Users")
2.             .ToQuery()
3.             .And(users => users.Field("Id").LessValue(100));

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sql: SELECT * FROM [Employees] AS e INNER JOIN [Departments] AS d ON e.[DepartmentId]=d.[Id] WHERE e.[Age]>30 AND d.[Manager]='CEO'
可以设置别名

1.         var joinOn = SimpleDB.From("Employees").SqlJoin(SimpleDB.From("Departments"))
2.             .On(static (t1, t2) => t1.Field("DepartmentId").Equal(t2.Field("Id")))
3.             .WhereLeft(t1 => t1.Field("Age").GreaterValue(30))
4.             .WhereRight(t2 => t2.Field("Manager").EqualValue("CEO"));

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2、Query极简联表 

1.         var joinOn = SimpleDB.From("Employees").SqlJoin(SimpleDB.From("Departments"));
2.         var (t1, t2) = (joinOn.Left, joinOn.Source);
3.         joinOn.On(t1.Field("DepartmentId").Equal(t2.Field("Id")));
4.         var joinTable = joinOn.Root
5.             .Where(t1.Field("Age").GreaterValue(30))
6.             .Where(t2.Field("Manager").EqualValue("CEO"));

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sql: SELECT * FROM [Employees] AS t1 INNER JOIN [Departments] AS t2 ON t1.[DepartmentId]=t2.[Id] WHERE t1.[Age]>30 AND t2.[Manager]='CEO'
Query也可以设置别名

1.         var e = SimpleDB.From("Employees").As("e");
2.         var d = SimpleDB.From("Departments").As("d");
3.         var joinOn = e.SqlJoin(d)
4.             .On(e.Field("DepartmentId").Equal(d.Field("Id")));
5.         var joinTable = joinOn.Root
6.             .Where(e.Field("Age").GreaterValue(30))
7.             .Where(d.Field("Manager").EqualValue("CEO"));

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 sql: SELECT * FROM [Employees] AS e INNER JOIN [Departments] AS d ON e.[DepartmentId]=d.[Id] WHERE e.[Age]>30 AND d.[Manager]='CEO'
通过Field查询,既不需要自定义表类型,也不需要给表定义列,就可以畅通无阻的进行sql查询，这也一种不错的选项
 

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