FreeSql在查询数据下足了功能,链式查询语法、多表查询、表达式函数支持得非常到位。
IFreeSql fsql = new FreeSql.FreeSqlBuilder()
.UseConnectionString(FreeSql.DataType.MySql, "Data Source=127.0.0.1;Port=3306;User ID=root;Password=root;Initial Catalog=cccddd;Charset=utf8;SslMode=none;Max pool size=10")
.Build();
[Table(Name = "tb_topic")]
class Topic {
[Column(IsIdentity = true, IsPrimary = true)]
public int Id { get; set; }
public int Clicks { get; set; }
public int TestTypeInfoGuid { get; set; }
public TestTypeInfo Type { get; set; }
public string Title { get; set; }
public DateTime CreateTime { get; set; }
}
class TestTypeInfo {
public int Guid { get; set; }
public int ParentId { get; set; }
public TestTypeParentInfo Parent { get; set; }
public string Name { get; set; }
public List<Topic> Topics { get; set; }
}
class TestTypeParentInfo {
public int Id { get; set; }
public string Name { get; set; }
}
ISelect<Topic> select => fsql.Select<Topic>();
利用导航属性联表
sql = select.LeftJoin(a => a.Type.Guid == a.TestTypeInfoGuid).ToSql();
//SELECT a.`Id`, a.`Clicks`, a.`TestTypeInfoGuid`, a__Type.`Guid`, a__Type.`ParentId`, a__Type.`Name`, a.`Title`, a.`CreateTime`
//FROM `tb_topic` a
//LEFT JOIN `TestTypeInfo` a__Type ON a__Type.`Guid` = a.`TestTypeInfoGuid`
sql = select
.LeftJoin(a => a.Type.Guid == a.TestTypeInfoGuid)
.LeftJoin(a => a.Type.Parent.Id == a.Type.ParentId).ToSql();
//SELECT a.`Id`, a.`Clicks`, a.`TestTypeInfoGuid`, a__Type.`Guid`, a__Type.`ParentId`, a__Type.`Name`, a.`Title`, a.`CreateTime`
//FROM `tb_topic` a
//LEFT JOIN `TestTypeInfo` a__Type ON a__Type.`Guid` = a.`TestTypeInfoGuid`
//LEFT JOIN `TestTypeParentInfo` a__Type__Parent ON a__Type__Parent.`Id` = a__Type.`ParentId`
没有导航属性联表
sql = select.LeftJoin<TestTypeInfo>((a, b) => b.Guid == a.TestTypeInfoGuid).ToSql();
//SELECT a.`Id`, a.`Clicks`, a.`TestTypeInfoGuid`, b.`Guid`, b.`ParentId`, b.`Name`, a.`Title`, a.`CreateTime`
//FROM `tb_topic` a
//LEFT JOIN `TestTypeInfo` b ON b.`Guid` = a.`TestTypeInfoGuid`
sql = select
.LeftJoin<TestTypeInfo>((a, b) => b.Guid == a.TestTypeInfoGuid)
.LeftJoin<TestTypeParentInfo>((a, c) => c.Id == a.Type.ParentId).ToSql();
//SELECT a.`Id`, a.`Clicks`, a.`TestTypeInfoGuid`, b.`Guid`, b.`ParentId`, b.`Name`, a.`Title`, a.`CreateTime`
//FROM `tb_topic` a
//LEFT JOIN `TestTypeInfo` b ON b.`Guid` = a.`TestTypeInfoGuid`
//LEFT JOIN `TestTypeParentInfo` c ON c.`Id` = b.`ParentId`
联表任意查
sql = select.From<TestTypeInfo, TestTypeParentInfo>((s, b, c) => s
.LeftJoin(a => a.TestTypeInfoGuid == b.Guid)
.LeftJoin(a => b.ParentId == c.Id)).ToSql();
//SELECT a.`Id`, a.`Clicks`, a.`TestTypeInfoGuid`, b.`Guid`, b.`ParentId`, b.`Name`, a.`Title`, a.`CreateTime`
//FROM `tb_topic` a
//LEFT JOIN `TestTypeInfo` b ON a.`TestTypeInfoGuid` = b.`Guid`
//LEFT JOIN `TestTypeParentInfo` c ON b.`ParentId` = c.`Id`
或者:
sql = fsql.Select<Topic, TestTypeInfo, TestTypeParentInfo>()
.LeftJoin((a, b, c) => a.TestTypeInfoGuid == b.Guid)
.LeftJoin((a, b, c) => b.ParentId == c.Id).ToSql();
//SELECT a.`Id`, a.`Clicks`, a.`TestTypeInfoGuid`, b.`Guid`, b.`ParentId`, b.`Name`, a.`Title`, a.`CreateTime`
//FROM `tb_topic` a
//LEFT JOIN `TestTypeInfo` b ON a.`TestTypeInfoGuid` = b.`Guid`
//LEFT JOIN `TestTypeParentInfo` c ON b.`ParentId` = c.`Id`
原生SQL联表
sql = select.LeftJoin("TestTypeInfo b on b.Guid = a.TestTypeInfoGuid and b.Name = ?bname", new { bname = "xxx" }).ToSql();
//SELECT a.`Id`, a.`Clicks`, a.`TestTypeInfoGuid`, a.`Title`, a.`CreateTime`
//FROM `tb_topic` a
//LEFT JOIN TestTypeInfo b on b.Guid = a.TestTypeInfoGuid and b.Name = ?bname