我试图编写一个C＃程序（.Net核心2.1），以从ms sql服务器数据库中读取给定表的所有检查约束。我正在使用sys.check_constraints表获取此信息，当我尝试使用ado.net数据读取器读取此信息时，尽管该表中的“定义”列具有值，但始终为空。
SQL脚本（DDL，用于获取CheckConstraints的存储过程，存储过程的执行状态）
GO
/****** Object: Table [dbo].[Customer] Script Date: 7/10/2019 3:24:22 PM ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE TABLE [dbo].[Customer](
[Id] [bigint] IDENTITY(1,1) NOT NULL,
[CompanyId] [smallint] NOT NULL,
[Prefix] [varchar](4) NOT NULL,
[FirstName] [varchar](50) NOT NULL,
[LastName] [varchar](50) NOT NULL,
[MiddleName] [varchar](50) NULL,
[Suffix] [varchar](4) NULL,
[NickName] [varchar](10) NULL,
[ProfilePictureName] [varchar](50) NULL,
[Company] [varchar](100) NULL,
[DateOfBirth] [date] NOT NULL,
[DateOfDeath] [date] NULL,
[Gender] [char](1) NOT NULL,
[Type] [varchar](10) NOT NULL,
[IsActive] [char](1) NULL,
[CreatedBy] [varchar](50) NOT NULL,
[CreatedOn] [datetime2](7) NOT NULL,
[UpdatedBy] [varchar](50) NULL,
[UpdatedOn] [datetime2](7) NULL,
[Process] [varchar](100) NULL,
[MessageId] [varchar](50) NOT NULL,
[SysStartDate] [datetime2](2) GENERATED ALWAYS AS ROW START NOT NULL,
[SysEndDate] [datetime2](2) GENERATED ALWAYS AS ROW END NOT NULL,
CONSTRAINT [PK_CUSTOMER] PRIMARY KEY CLUSTERED
(
[Id] ASC,
[CompanyId] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY],
PERIOD FOR SYSTEM_TIME ([SysStartDate], [SysEndDate])
) ON [PRIMARY]
WITH
(
SYSTEM_VERSIONING = ON ( HISTORY_TABLE = [dbo].[MSSQL_TemporalHistoryFor_601769201] )
)
GO
ALTER TABLE [dbo].[Customer] ADD DEFAULT ('Y') FOR [IsActive]
GO
ALTER TABLE [dbo].[Customer] WITH CHECK ADD CONSTRAINT [CUSTOMER_PREFIX_CHECK] CHECK (([Prefix]='Dr' OR [Prefix]='Miss' OR [Prefix]='Ms' OR [Prefix]='Mrs' OR [Prefix]='Mr'))
GO
ALTER TABLE [dbo].[Customer] CHECK CONSTRAINT [CUSTOMER_PREFIX_CHECK]
GO
ALTER TABLE [dbo].[Customer] WITH CHECK ADD CONSTRAINT [CUSTOMER_SUFFIX_CHECK] CHECK (([Suffix]='RN' OR [Suffix]='MD' OR [Suffix]='ESQ' OR [Suffix]='DO' OR [Suffix]='DDS' OR [Suffix]='DDM' OR [Suffix]='III' OR [Suffix]='II' OR [Suffix]='I' OR [Suffix]='Sr' OR [Suffix]='Jr'))
GO
ALTER TABLE [dbo].[Customer] CHECK CONSTRAINT [CUSTOMER_SUFFIX_CHECK]
GO
ALTER TABLE [dbo].[Customer] WITH CHECK ADD CONSTRAINT [CUSTOMER_TYPE_CHECK] CHECK (([Type]='Customer' OR [Type]='VENDOR' OR [Type]='INSIDER' OR [Type]='ANALYST' OR [Type]='INVESTOR'))
GO
ALTER TABLE [dbo].[Customer] CHECK CONSTRAINT [CUSTOMER_TYPE_CHECK]
GO
CREATE PROCEDURE [dbo].[GetCheckConstraints_Dup](@tableName as varchar(200))
AS
BEGIN
select
col.[name] as column_name,
con.[definition] As [constraint_value]
from sys.check_constraints con
left outer join sys.objects t
on con.parent_object_id = t.object_id
left outer join sys.all_columns col
on con.parent_column_id = col.column_id
and con.parent_object_id = col.object_id
where t.[name]=@tableName and con.is_disabled=0
order by con.name;
End;
GO
exec GetCheckConstraints_Dup 'Customer'
C＃
public static List<Constraints> GetConstraints(string tableName,string connectionString)
{
var constraints = new List<Constraints>();
using (SqlConnection connection = new SqlConnection(connectionString))
{
//SqlDataReader
connection.Open();
SqlCommand cmd = new SqlCommand("DBO.GetCheckConstraints_Dup", connection);
cmd.CommandType = CommandType.StoredProcedure;
cmd.Parameters.Add("@tableName", SqlDbType.VarChar).Value = tableName;
using (SqlDataReader dataReader = cmd.ExecuteReader())
{
while (dataReader.Read())
{
constraints.Add(new Constraints() { FieldName = dataReader["column_name"].ToString(), Constraint = ConstraintType.Check, ConstraintValue = dataReader["constraint_value"].ToString() });
}
}
}
return constraints;
}
答案 0 :(得分：0)
对我来说没有复制品。会复制吗？
using System;
using System.Collections.Generic;
using System.Data;
using System.Data.SqlClient;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace ConsoleApp18
{
class Program
{
static string ddl = @"
GO
--if exists (select * from sys.tables where name = 'Customer')
-- begin
-- ALTER TABLE [dbo].[Customer] SET ( SYSTEM_VERSIONING = OFF)
-- DROP TABLE [dbo].[Customer]
-- DROP TABLE [dbo].[MSSQL_TemporalHistoryFor_601769201]
--end
go
/****** Object: Table [dbo].[Customer] Script Date: 7/10/2019 3:24:22 PM ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE TABLE [dbo].[Customer](
[Id] [bigint] IDENTITY(1,1) NOT NULL,
[CompanyId] [smallint] NOT NULL,
[Prefix] [varchar](4) NOT NULL,
[FirstName] [varchar](50) NOT NULL,
[LastName] [varchar](50) NOT NULL,
[MiddleName] [varchar](50) NULL,
[Suffix] [varchar](4) NULL,
[NickName] [varchar](10) NULL,
[ProfilePictureName] [varchar](50) NULL,
[Company] [varchar](100) NULL,
[DateOfBirth] [date] NOT NULL,
[DateOfDeath] [date] NULL,
[Gender] [char](1) NOT NULL,
[Type] [varchar](10) NOT NULL,
[IsActive] [char](1) NULL,
[CreatedBy] [varchar](50) NOT NULL,
[CreatedOn] [datetime2](7) NOT NULL,
[UpdatedBy] [varchar](50) NULL,
[UpdatedOn] [datetime2](7) NULL,
[Process] [varchar](100) NULL,
[MessageId] [varchar](50) NOT NULL,
[SysStartDate] [datetime2](2) GENERATED ALWAYS AS ROW START NOT NULL,
[SysEndDate] [datetime2](2) GENERATED ALWAYS AS ROW END NOT NULL,
CONSTRAINT [PK_CUSTOMER] PRIMARY KEY CLUSTERED
(
[Id] ASC,
[CompanyId] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY],
PERIOD FOR SYSTEM_TIME ([SysStartDate], [SysEndDate])
) ON [PRIMARY]
WITH
(
SYSTEM_VERSIONING = ON ( HISTORY_TABLE = [dbo].[MSSQL_TemporalHistoryFor_601769201] )
)
GO
ALTER TABLE [dbo].[Customer] ADD DEFAULT ('Y') FOR [IsActive]
GO
ALTER TABLE [dbo].[Customer] WITH CHECK ADD CONSTRAINT [CUSTOMER_PREFIX_CHECK] CHECK (([Prefix]='Dr' OR [Prefix]='Miss' OR [Prefix]='Ms' OR [Prefix]='Mrs' OR [Prefix]='Mr'))
GO
ALTER TABLE [dbo].[Customer] CHECK CONSTRAINT [CUSTOMER_PREFIX_CHECK]
GO
ALTER TABLE [dbo].[Customer] WITH CHECK ADD CONSTRAINT [CUSTOMER_SUFFIX_CHECK] CHECK (([Suffix]='RN' OR [Suffix]='MD' OR [Suffix]='ESQ' OR [Suffix]='DO' OR [Suffix]='DDS' OR [Suffix]='DDM' OR [Suffix]='III' OR [Suffix]='II' OR [Suffix]='I' OR [Suffix]='Sr' OR [Suffix]='Jr'))
GO
ALTER TABLE [dbo].[Customer] CHECK CONSTRAINT [CUSTOMER_SUFFIX_CHECK]
GO
ALTER TABLE [dbo].[Customer] WITH CHECK ADD CONSTRAINT [CUSTOMER_TYPE_CHECK] CHECK (([Type]='Customer' OR [Type]='VENDOR' OR [Type]='INSIDER' OR [Type]='ANALYST' OR [Type]='INVESTOR'))
GO
ALTER TABLE [dbo].[Customer] CHECK CONSTRAINT [CUSTOMER_TYPE_CHECK]
GO
CREATE OR ALTER PROCEDURE [dbo].[GetCheckConstraints_Dup](@tableName as varchar(200))
AS
BEGIN
select
col.[name] as column_name,
con.[definition] As [constraint_value]
from sys.check_constraints con
left outer join sys.objects t
on con.parent_object_id = t.object_id
left outer join sys.all_columns col
on con.parent_column_id = col.column_id
and con.parent_object_id = col.object_id
where t.[name]=@tableName and con.is_disabled=0
order by con.name;
End;
GO
";
static IEnumerable<string> GetBatches(string script)
{
var rdr = new System.IO.StringReader(script);
var sb = new StringBuilder();
while (true)
{
var l = rdr.ReadLine()?.Trim();
if (l == null)
{
var batch = sb.ToString().Trim();
if (batch.Length > 0)
yield return sb.ToString();
break;
}
else if (l.Equals( "GO", StringComparison.OrdinalIgnoreCase))
{
var batch = sb.ToString().Trim();
if (batch.Length > 0)
yield return sb.ToString();
sb.Clear();
}
else
{
sb.AppendLine(l.Trim());
}
}
}
static void Main(string[] args)
{
var constr = "Server=localhost;database=tempdb;integrated security=true";
using (var con = new SqlConnection(constr))
{
con.Open();
foreach (var batch in GetBatches(ddl))
{
var cmd = con.CreateCommand();
cmd.CommandText = batch;
cmd.ExecuteNonQuery();
}
var constraints = GetConstraints("Customer", constr);
foreach (var constraint in constraints)
{
Console.WriteLine($"{constraint.FieldName} {constraint.ConstraintValue}");
}
}
Console.WriteLine("Hit any key to exit");
Console.ReadKey();
}
public static List<Constraints> GetConstraints(string tableName, string connectionString)
{
var constraints = new List<Constraints>();
using (SqlConnection connection = new SqlConnection(connectionString))
{
//SqlDataReader
connection.Open();
SqlCommand cmd = new SqlCommand("DBO.GetCheckConstraints_Dup", connection);
cmd.CommandType = CommandType.StoredProcedure;
cmd.Parameters.Add("@tableName", SqlDbType.VarChar).Value = tableName;
using (SqlDataReader dataReader = cmd.ExecuteReader())
{
while (dataReader.Read())
{
constraints.Add(new Constraints() { FieldName = dataReader["column_name"].ToString(), Constraint = "Check", ConstraintValue = dataReader["constraint_value"].ToString() });
}
}
}
return constraints;
}
public class Constraints
{
public string FieldName { get; internal set; }
public string Constraint { get; internal set; }
public string ConstraintValue { get; internal set; }
}
}
}