如何从SQL Server表对象生成类?
我说的不是使用ORM。我只需要创建实体(简单类)。喜欢的东西:
public class Person
{
public string Name { get;set; }
public string Phone { get;set; }
}
给定一个表，比如:
+----+-------+----------------+
| ID | Name | Phone |
+----+-------+----------------+
| 1 | Alice | (555) 555-5550 |
| 2 | Bob | (555) 555-5551 |
| 3 | Cathy | (555) 555-5552 |
+----+-------+----------------+
当前回答
要打印带有注释(摘要)的NULLABLE属性，使用这个。 这是对第一个答案的轻微修改
declare @TableName sysname = 'TableName'
declare @result varchar(max) = 'public class ' + @TableName + '
{'
select @result = @result
+ CASE WHEN ColumnDesc IS NOT NULL THEN '
/// <summary>
/// ' + ColumnDesc + '
/// </summary>' ELSE '' END
+ '
public ' + ColumnType + ' ' + ColumnName + ' { get; set; }'
from
(
select
replace(col.name, ' ', '_') ColumnName,
column_id,
case typ.name
when 'bigint' then 'long'
when 'binary' then 'byte[]'
when 'bit' then 'bool'
when 'char' then 'String'
when 'date' then 'DateTime'
when 'datetime' then 'DateTime'
when 'datetime2' then 'DateTime'
when 'datetimeoffset' then 'DateTimeOffset'
when 'decimal' then 'decimal'
when 'float' then 'float'
when 'image' then 'byte[]'
when 'int' then 'int'
when 'money' then 'decimal'
when 'nchar' then 'char'
when 'ntext' then 'string'
when 'numeric' then 'decimal'
when 'nvarchar' then 'String'
when 'real' then 'double'
when 'smalldatetime' then 'DateTime'
when 'smallint' then 'short'
when 'smallmoney' then 'decimal'
when 'text' then 'String'
when 'time' then 'TimeSpan'
when 'timestamp' then 'DateTime'
when 'tinyint' then 'byte'
when 'uniqueidentifier' then 'Guid'
when 'varbinary' then 'byte[]'
when 'varchar' then 'string'
else 'UNKNOWN_' + typ.name
END + CASE WHEN col.is_nullable=1 AND typ.name NOT IN ('binary', 'varbinary', 'image', 'text', 'ntext', 'varchar', 'nvarchar', 'char', 'nchar') THEN '?' ELSE '' END ColumnType,
colDesc.colDesc AS ColumnDesc
from sys.columns col
join sys.types typ on
col.system_type_id = typ.system_type_id AND col.user_type_id = typ.user_type_id
OUTER APPLY (
SELECT TOP 1 CAST(value AS NVARCHAR(max)) AS colDesc
FROM
sys.extended_properties
WHERE
major_id = col.object_id
AND
minor_id = COLUMNPROPERTY(major_id, col.name, 'ColumnId')
) colDesc
where object_id = object_id(@TableName)
) t
order by column_id
set @result = @result + '
}'
print @result
其他回答
Postgres DB -> c#的另一个解决方案
兼容NpgSQL 添加DataAnnotations
SELECT
CASE
WHEN c.is_nullable ='NO' THEN '[Required]'||chr(10)
ELSE '' END
||CASE
WHEN c.data_type = 'character varying' THEN format('[StringLength(%s)]',c.character_maximum_length)||chr(10)
ELSE '' END
||'public '
||CASE
WHEN c.data_type = 'integer' THEN 'int'
WHEN c.data_type = 'boolean' THEN 'bool'
WHEN c.data_type = 'double precision' THEN 'double'
WHEN c.data_type = 'uuid' THEN 'Guid'
WHEN c.data_type = 'character varying' THEN 'string'
WHEN c.data_type = 'timestamp without time zone' THEN 'DateTime'
WHEN c.data_type = 'bigint' THEN 'long'
WHEN c.data_type = 'bytea' THEN 'byte[]'
ELSE 'object' END
||CASE
WHEN c.is_nullable='YES' AND NOT c.data_type = 'character varying' THEN '? '
ELSE ' ' END
||c.column_name||' {get;set;}'
,c.*
FROM information_schema."columns" c
WHERE 1=1
AND c.table_name='YOUR_TABLE_NAME'
Java类生成
declare @TableName varchar(max) = 'Restaurants'
declare @Templete varchar(max) = '
public @ColumnType @ColumnName ; // @ColumnDesc
public @ColumnType get@ColumnName()
{
return this.@ColumnName;
}
public void set@ColumnName(@ColumnType @ColumnName)
{
this.@ColumnName=@ColumnName;
}
'
declare @before varchar(max)='public class @TableName
{'
declare @after varchar(max)='
}'
declare @result varchar(max)
set @before =replace(@before,'@TableName',@TableName)
set @result=@before
select @result = @result
+ replace(replace(replace(replace(replace(@Templete,'@ColumnType',ColumnType) ,'@ColumnName',ColumnName) ,'@ColumnDesc',ColumnDesc),'@ISPK',ISPK),'@max_length',max_length)
from
(
select
column_id,
replace(col.name, ' ', '_') ColumnName,
typ.name as sqltype,
typ.max_length,
is_identity,
pkk.ISPK,
case typ.name
when 'bigint' then 'long'
when 'binary' then 'byte[]'
when 'bit' then 'bool'
when 'char' then 'String'
when 'date' then 'DateTime'
when 'datetime' then 'DateTime'
when 'datetime2' then 'DateTime'
when 'datetimeoffset' then 'DateTimeOffset'
when 'decimal' then 'decimal'
when 'float' then 'float'
when 'image' then 'byte[]'
when 'int' then 'int'
when 'money' then 'decimal'
when 'nchar' then 'char'
when 'ntext' then 'string'
when 'numeric' then 'decimal'
when 'nvarchar' then 'String'
when 'real' then 'double'
when 'smalldatetime' then 'DateTime'
when 'smallint' then 'short'
when 'smallmoney' then 'decimal'
when 'text' then 'String'
when 'time' then 'TimeSpan'
when 'timestamp' then 'DateTime'
when 'tinyint' then 'byte'
when 'uniqueidentifier' then 'Guid'
when 'varbinary' then 'byte[]'
when 'varchar' then 'string'
else 'UNKNOWN_' + typ.name
END + CASE WHEN col.is_nullable=1 AND typ.name NOT IN ('binary', 'varbinary', 'image', 'text', 'ntext', 'varchar', 'nvarchar', 'char', 'nchar') THEN '?' ELSE '' END ColumnType,
isnull(colDesc.colDesc,'') AS ColumnDesc
from sys.columns col
join sys.types typ on
col.system_type_id = typ.system_type_id AND col.user_type_id = typ.user_type_id
left join
(
SELECT c.name AS 'ColumnName', CASE WHEN dd.pk IS NULL THEN 'false' ELSE 'true' END ISPK
FROM sys.columns c
JOIN sys.tables t ON c.object_id = t.object_id
LEFT JOIN (SELECT K.COLUMN_NAME , C.CONSTRAINT_TYPE as pk
FROM INFORMATION_SCHEMA.KEY_COLUMN_USAGE AS K
LEFT JOIN INFORMATION_SCHEMA.TABLE_CONSTRAINTS AS C
ON K.TABLE_NAME = C.TABLE_NAME
AND K.CONSTRAINT_NAME = C.CONSTRAINT_NAME
AND K.CONSTRAINT_CATALOG = C.CONSTRAINT_CATALOG
AND K.CONSTRAINT_SCHEMA = C.CONSTRAINT_SCHEMA
WHERE K.TABLE_NAME = @TableName) as dd
ON dd.COLUMN_NAME = c.name
WHERE t.name = @TableName
) pkk on ColumnName=col.name
OUTER APPLY (
SELECT TOP 1 CAST(value AS NVARCHAR(max)) AS colDesc
FROM
sys.extended_properties
WHERE
major_id = col.object_id
AND
minor_id = COLUMNPROPERTY(major_id, col.name, 'ColumnId')
) colDesc
where object_id = object_id(@TableName)
) t
set @result=@result+@after
select @result
--print @result
为了感谢Alex的解决方案和Guilherme的要求，我为MySQL生成c#类做了这个
set @schema := 'schema_name';
set @table := 'table_name';
SET group_concat_max_len = 2048;
SELECT
concat('public class ', @table, '\n{\n', GROUP_CONCAT(a.property_ SEPARATOR '\n'), '\n}') class_
FROM
(select
CONCAT(
'\tpublic ',
case
when DATA_TYPE = 'bigint' then 'long'
when DATA_TYPE = 'BINARY' then 'byte[]'
when DATA_TYPE = 'bit' then 'bool'
when DATA_TYPE = 'char' then 'string'
when DATA_TYPE = 'date' then 'DateTime'
when DATA_TYPE = 'datetime' then 'DateTime'
when DATA_TYPE = 'datetime2' then 'DateTime'
when DATA_TYPE = 'datetimeoffset' then 'DateTimeOffset'
when DATA_TYPE = 'decimal' then 'decimal'
when DATA_TYPE = 'double' then 'double'
when DATA_TYPE = 'float' then 'float'
when DATA_TYPE = 'image' then 'byte[]'
when DATA_TYPE = 'int' then 'int'
when DATA_TYPE = 'money' then 'decimal'
when DATA_TYPE = 'nchar' then 'char'
when DATA_TYPE = 'ntext' then 'string'
when DATA_TYPE = 'numeric' then 'decimal'
when DATA_TYPE = 'nvarchar' then 'string'
when DATA_TYPE = 'real' then 'double'
when DATA_TYPE = 'smalldatetime' then 'DateTime'
when DATA_TYPE = 'smallint' then 'short'
when DATA_TYPE = 'smallmoney' then 'decimal'
when DATA_TYPE = 'text' then 'string'
when DATA_TYPE = 'time' then 'TimeSpan'
when DATA_TYPE = 'timestamp' then 'DateTime'
when DATA_TYPE = 'tinyint' then 'byte'
when DATA_TYPE = 'uniqueidentifier' then 'Guid'
when DATA_TYPE = 'varbinary' then 'byte[]'
when DATA_TYPE = 'varchar' then 'string'
else '_UNKNOWN_'
end, ' ',
COLUMN_NAME, ' {get; set;}') as property_
FROM INFORMATION_SCHEMA.COLUMNS
WHERE table_name = @table AND table_schema = @schema) a
;
谢谢Alex和Guilherme!
设置@TableName为你的表名。
declare @TableName sysname = 'TableName'
declare @Result varchar(max) = 'public class ' + @TableName + '
{'
select @Result = @Result + '
public ' + ColumnType + NullableSign + ' ' + ColumnName + ' { get; set; }
'
from
(
select
replace(col.name, ' ', '_') ColumnName,
column_id ColumnId,
case typ.name
when 'bigint' then 'long'
when 'binary' then 'byte[]'
when 'bit' then 'bool'
when 'char' then 'string'
when 'date' then 'DateTime'
when 'datetime' then 'DateTime'
when 'datetime2' then 'DateTime'
when 'datetimeoffset' then 'DateTimeOffset'
when 'decimal' then 'decimal'
when 'float' then 'double'
when 'image' then 'byte[]'
when 'int' then 'int'
when 'money' then 'decimal'
when 'nchar' then 'string'
when 'ntext' then 'string'
when 'numeric' then 'decimal'
when 'nvarchar' then 'string'
when 'real' then 'float'
when 'smalldatetime' then 'DateTime'
when 'smallint' then 'short'
when 'smallmoney' then 'decimal'
when 'text' then 'string'
when 'time' then 'TimeSpan'
when 'timestamp' then 'long'
when 'tinyint' then 'byte'
when 'uniqueidentifier' then 'Guid'
when 'varbinary' then 'byte[]'
when 'varchar' then 'string'
else 'UNKNOWN_' + typ.name
end ColumnType,
case
when col.is_nullable = 1 and typ.name in ('bigint', 'bit', 'date', 'datetime', 'datetime2', 'datetimeoffset', 'decimal', 'float', 'int', 'money', 'numeric', 'real', 'smalldatetime', 'smallint', 'smallmoney', 'time', 'tinyint', 'uniqueidentifier')
then '?'
else ''
end NullableSign
from sys.columns col
join sys.types typ on
col.system_type_id = typ.system_type_id AND col.user_type_id = typ.user_type_id
where object_id = object_id(@TableName)
) t
order by ColumnId
set @Result = @Result + '
}'
print @Result
我只是想表达我的意见
0) QueryFirst https://marketplace.visualstudio.com/items?itemName=bbsimonbb.QueryFirst Query-first is a visual studio extension for working intelligently with SQL in C# projects. Use the provided .sql template to develop your queries. When you save the file, Query-first runs your query, retrieves the schema and generates two classes and an interface: a wrapper class with methods Execute(), ExecuteScalar(), ExecuteNonQuery() etc, its corresponding interface, and a POCO encapsulating a line of results.
1) Sql2Objects 从查询结果开始创建类(但不是DAL)
2) https://learn.microsoft.com/en-us/ef/ef6/resources/tools
3) https://visualstudiomagazine.com/articles/2012/12/11/sqlqueryresults-code-generation.aspx
4) http://www.codesmithtools.com/product/generator#features
