类型映射

类型映射（默认）

提示：因排版问题，不显示所有支持的数据库

csharp	MySql	SqlServer	PostgreSQL	Oracle	Sqlite	达梦
bool | bool?	bit(1)	bit	bool	number(1)	boolean	number(1)
sbyte | sbyte?	tinyint(3)	smallint	int2	number(4)	smallint	number(4)
short | short?	smallint(6)	smallint	int2	number(6)	smallint	number(6)
int | int?	int(11)	int	int4	number(11)	integer	number(11)
long | long?	bigint(20)	bigint	int8	number(21)	integer	number(21)
byte | byte?	tinyint(3) unsigned	tinyint	int2	number(3)	int2	number(3)
ushort | ushort?	smallint(5) unsigned	int	int4	number(5)	unsigned	number(5)
uint | uint?	int(10) unsigned	bigint	int8	number(10)	decimal(10,0)	number(10)
ulong | ulong?	bigint(20) unsigned	decimal(20,0)	numeric(20,0)	number(20)	decimal(21,0)	number(20)
double | double?	double	float	float8	float(126)	double	double
float | float?	float	real	float4	float(63)	float	real
decimal | decimal?	decimal(10,2)	decimal(10,2)	numeric(10,2)	number(10,2)	decimal(10,2)	number(10,2)
Guid | Guid?	char(36)	uniqueidentifier	uuid	char(36 CHAR)	character(36)	char(36)
TimeSpan | TimeSpan?	time	time	time	interval day(2) to second(6)	bigint	-
DateTime | DateTime?	datetime	datetime	timestamp	timestamp(6)	datetime	timestamp(6)
DateTimeOffset | DateTimeOffset?	-	datetimeoffset	-	timestamp(6) with local time zone	-	timestamp(6)
Enum | Enum?	enum	int	int4	number(16)	mediumint	number(16)
FlagsEnum | FlagsEnum?	set	bigint	int8	number(32)	bigint	number(32)
byte[]	varbinary(255)	varbinary(255)	bytea	blob	blob	blob
string	varchar(255)	nvarchar(255)	varchar(255)	nvarchar2(255)	nvarchar(255)	nvarchar2(255)

string 指定长度 [Column(DbType = "varchar(max)")] 或者 [MaxLength(-1)] 或者 [Column(StringLength = -1)]，当长度 -1 时产生的映射如下：

MySql	PostgreSQL	SqlServer	Oracle	Sqlite	Firebird	DuckDB	MsAccess	达梦	金仓
text	text	varchar(max)	nclob	text	blob sub_type 1	text	longtext	text	text

注意：MySql [MaxLength(-2)] 或者 [Column(StringLength = -2)] 映射类型 longtext

decimal 指定长度 [Column(Precision = 10, Scale = 2)]

MapType

使用 MapType 枚举 -> string/int 等等如下：

class Table
{
    [Column(MapType = typeof(string))]
    public PeopleType t1 { get; set; }

    [Column(MapType = typeof(int))]
    public PeopleType t2 { get; set; }

    [Column(MapType = typeof(string))]
    public BigInteger t3 { get; set; }
}
public enum PeopleType { 中国人, abc, 香港 }

Json

dotnet add package FreeSql.Extensions.JsonMap

fsql.UseJsonMap(); //开启功能

class Table
{
    public int Id { get; set; }

    [JsonMap]
    public TableOptions Options { get; set; }
}
class TableOptions
{
    public int Value1 { get; set; }
    public string Value2 { get; set; }
}

fsql.Select<Table>().Where(a => a.Options.Value1 == 100 && a.Options.Value2 == "xx").ToList();
//WHERE json_extract(a."Options",'$.Value1') = 100 AND json_extract(a."Options",'$.Value2') = 'xx'

也可以使用 string 映射 JSON，拉姆达表达式内使用自定义函数解析。

##DateOnly/TimeOnly

目前只有 FreeSql.Provider.SqlServer/PostgreSQL/MySql/MySqlConnector/KingbaseES/Duckdb 几个包实现了映射（v3.5.100）

DateOnly/TimeOnly 定义在 .net6/7/8 适配非常难受，其他 Provider 可参考 TypeHandlers（自定义） 解决映射。

TypeHandlers（自定义）

FreeSql.Internal.Utils.TypeHandlers.TryAdd(typeof(JsonPoco), new JsonPocoTypeHandler());
FreeSql.Internal.Utils.TypeHandlers.TryAdd(typeof(DateOnly), new DateOnlyTypeHandler());
FreeSql.Internal.Utils.TypeHandlers.TryAdd(typeof(DateTimeOffset), new DateTimeOffsetTypeHandler());

class Product
{
    public JsonPoco json { get; set; }
    public DateOnly date { get; set; }
    public DateTimeOffset dateTimeOffset { get; set; }
}
class JsonPoco
{
    public int a { get; set; }
    public int b { get; set; }
}
class JsonPocoTypeHandler : TypeHandler<JsonPoco>
{
    public override object Serialize(JsonPoco value) => JsonConvert.SerializeObject(value);
    public override JsonPoco Deserialize(object value) => JsonConvert.DeserializeObject<JsonPoco>((string)value);
    public override void FluentApi(ColumnFluent col) => col.MapType(typeof(string)).StringLength(-1);
}
class DateOnlyTypeHandler : TypeHandler<DateOnly>
{
    public override object Serialize(DateOnly value) => value.ToString("yyyy-MM-dd");
    public override DateOnly Deserialize(object value) => DateOnly.TryParse(string.Concat(value), out var trydo) ? trydo : DateOnly.MinValue;
    public override void FluentApi(ColumnFluent col) => col.MapType(typeof(string)).StringLength(12);
}
class DateTimeOffsetTypeHandler : TypeHandler<DateTimeOffset>
{
    public override object Serialize(DateTimeOffset value) => value.ToUniversalTime().ToString("yyyy-MM-dd HH:mm:ss");
    public override DateTimeOffset Deserialize(object value) => DateTimeOffset.TryParse((string)value, out var dts) ? dts : DateTimeOffset.MinValue;
    public override void FluentApi(ColumnFluent col) => col.MapType(typeof(string)).DbType("datetime");
}

类型映射（特别）

FreeSql.Provider.MySql/MySqlConnector：

csharp	MySql
MygisPoint	point
MygisLineString	linestring
MygisPolygon	polygon
MygisMultiPoint	multipoint
MygisMultiLineString	multilinestring
MygisMultiPolygon	multipolygon

MySql 如果 int、byte类型，指定了 DbType="tinyint(1)",请注意，tinyint(1)在ado.net中默认将此值映射为bool类型，可在链接串中指定TreatTinyAsBoolean=false,使映射 tinyint(1) 为 SByte 而非 bool。

FreeSql.Provider.PostgreSQL：

csharp	PostgreSQL
BitArray	varbit(64)
NpgsqlPoint | NpgsqlPoint?	point
NpgsqlLine | NpgsqlLine?	line
NpgsqlLSeg | NpgsqlLSeg?	lseg
NpgsqlBox | NpgsqlBox?	box
NpgsqlPath | NpgsqlPath?	path
NpgsqlPolygon | NpgsqlPolygon?	polygon
NpgsqlCircle | NpgsqlCircle?	circle
(IPAddress Address, int Subnet) | (IPAddress Address, int Subnet)?	cidr
IPAddress	inet
PhysicalAddress	macaddr
NpgsqlRange<int> | NpgsqlRange<int>?	int4range
NpgsqlRange<long> | NpgsqlRange<long>?	int8range
NpgsqlRange<decimal> | NpgsqlRange<decimal>?	numrange
NpgsqlRange<DateTime> | NpgsqlRange<DateTime>?	tsrange
PostgisPoint	geometry
PostgisLineString	geometry
PostgisPolygon	geometry
PostgisMultiPoint	geometry
PostgisMultiLineString	geometry
PostgisMultiPolygon	geometry
PostgisGeometry	geometry
PostgisGeometryCollection	geometry
Dictionary<string, string>	hstore
JToken	jsonb
JObject	jsonb
JArray	jsonb
数组	以上所有类型都支持，包括默认类型

重写、重读

写入时重写 SQL、读取时重写 SQL，适合 geography 类型的读写场景。

[Column(
    DbType = "geography", 
    RewriteSql = "geography::STGeomFromText({0}, 4236)", 
    RereadSql = "{0}.STAsText()"
)]
public string geo { get; set; }

//插入：INSERT INTO [ts_geocrud01]([id], [geo]) VALUES(@id_0, geography::STGeomFromText(@geo_0, 4236))

//查询：SELECT TOP 1 a.[id], a.[geo].STAsText() 
//FROM [ts_geocrud01] a 
//WHERE (a.[id] = 'c7227d5e-0bcf-4b71-8f0f-d69a552fe84e')