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

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!

Visual Studio杂志发表了这篇文章:

为SQL查询结果生成。net POCO类

它有一个可下载的项目,你可以构建,给它你的SQL信息,它会为你制作出类。

现在,如果该工具刚刚为SELECT、INSERT和UPDATE创建了SQL命令....

你刚刚做了,只要你的表包含两列,并被称为'tblPeople'之类的东西。

您总是可以编写自己的SQL包装器。实际上我更喜欢这样做,我讨厌生成代码,以任何方式。

也许创建一个DAL类,并有一个名为GetPerson(int id)的方法,用于查询数据库中的person,然后从结果集中创建person对象。

我尝试过node.js,它对我来说工作得很好。

它将为您创建模型文件。您可以创建多个模型文件

前提条件:安装node.js

需要更改:

在你的工作区中创建index.js文件 在“allTable”中添加你的tables对象(截图中高亮显示) 更改文件夹路径(我已经给出了我的系统路径) 执行命令节点index.js

节点index.js

输出

const fs = require('fs/promises'); async function convertToDataType(dataArray, fileName) { let count = 0; let tempArray = []; var dataTypeArray = [ { "key": "bigint", "value": "long" }, { "key": "binary", "value": "byte[]" }, { "key": "bit", "value": "bool" }, { "key": "char", "value": "string" }, { "key": "date", "value": "DateTime" }, { "key": "datetime", "value": "DateTime" }, { "key": "datetime2", "value": "DateTime" }, { "key": "datetimeoffset", "value": "DateTimeOffset" }, { "key": "decimal", "value": "decimal" }, { "key": "float", "value": "double" }, { "key": "image", "value": "byte[]" }, { "key": "int", "value": "int" }, { "key": "money", "value": "decimal" }, { "key": "nchar", "value": "string" }, { "key": "ntext", "value": "string" }, { "key": "numeric", "value": "decimal" }, { "key": "nvarchar", "value": "string" }, { "key": "real", "value": "float" }, { "key": "smalldatetime", "value": "DateTime" }, { "key": "smallint", "value": "short" }, { "key": "smallmoney", "value": "decimal" }, { "key": "text", "value": "string" }, { "key": "time", "value": "TimeSpan" }, { "key": "timestamp", "value": "long" }, { "key": "tinyint", "value": "byte" }, { "key": "uniqueidentifier", "value": "Guid" }, { "key": "varbinary", "value": "byte[]" }, { "key": "varchar", "value": "string" } ] dataArray.map(i => { let objDataType = ''; objDataType = dataTypeArray.filter(data => data.key == i.split(' ')[1].replace('[', '').replace(']', ''))[0].value; if (objDataType == '') { count++; } let isNull = i.includes('NULL') && !(i.includes('varchar') || i.includes('bit')) ? '?' : ''; isNull = i.includes('NOT NULL') ? '' : isNull; const varValue = i.split(' ')[0].replace('[', '').replace(']', ''); if (count != 0) { console.warn(`\n\n\n ======> Error:: Check data type is missing. Datatype => ${i.split(' ')[1]} Object Name: ${fileName} \n\n\n`); } else { tempArray.push(`public ${objDataType}${isNull} ${varValue} { get; set; }`); } }); return tempArray; } async function convertToModel() { try { let allTable = { EmployeeAllowancesHistory: [ "[EmployeeAllowanceHistoryID] [int] NOT NULL", "[EmployeeID] [int] NOT NULL", "[AllowanceID] [int] NOT NULL", "[DateID] [int] NULL", "[Amount] [numeric] NOT NULL", "[Insured] [bit] NULL", "[ChangeDate] [datetime] NOT NULL", "[NewAmount] [numeric] NULL" ], Cities: [ "[CityID] [int] NOT NULL", "[CityCode] [varchar] NOT NULL", "[CityNameAr] [varchar] NULL", "[CityNameEn] [varchar] NULL", "[InKSA] [bit] NOT NULL", "[HighClass] [bit] NOT NULL", "[TravelDays] [int] NULL" ], Regions: [ "[RegionID] [int] NOT NULL", "[RegionCode] [nvarchar] NULL", "[RegionNameEn] [nvarchar] NULL", "[RegionNameAr] [nvarchar] NULL", "[CityID] [int] NULL" ] } for (var file in allTable) { const tableObject = await convertToDataType(allTable[file], file); let tempContent = "[key]"; tableObject.map(obj => { tempContent = `${tempContent} ${obj}` }); const content = `using System; using System.Collections.Generic; using System.Linq; using System.Threading.Tasks; namespace Core.Entities { public class ${file} { ${tempContent} } }` fs.writeFile(`/model_files/${file}.cs`, content); } console.log('Created successfully...'); } catch (err) { console.log(err); } } convertToModel();

要打印NULLABLE属性,请使用此命令。 它对Alex Aza的CASE语句块脚本进行了轻微修改。

declare @TableName sysname = 'TableName'
declare @result varchar(max) = 'public class ' + @TableName + '
{'

select @result = @result + '
    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 AS [ColumnType]
    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 column_id

set @result = @result  + '
}'

print @result