[英]Add string array to SQL query
我有一個包含標識符的字符串數組。 我想使用這些標識符從SQL獲取一些值。 有沒有一種將它們與字符串值添加到SqlCommand
參數的方法?
我想創建一個查詢,如:
select CaseList from MasterReportData where Id = 1 OR Id = 2 OR Id = 3
這是我的C#代碼:
public static List<string> GetCaseList(string[] masterIdList)
{
try
{
string query = " select CaseList from MasterReportData where @masterId";
SqlConnection conn = new SqlConnection(connString);
SqlCommand cmd = new SqlCommand(query, conn);
cmd.Parameters.AddWithValue("masterId", ***);
conn.Open();
using (SqlDataReader reader = cmd.ExecuteReader())
{
while (reader.Read())
{
list.Add(reader[0].ToString());
}
}
conn.Close();
}
catch (Exception e)
{
var err= 0;
}
return list;
}
您可以通過多種方法來執行此操作,但是我更喜歡創建可能值的臨時表。 這樣你可以做類似的事情
select CaseList from MasterReportData where Id IN(select Id from tempTable)
最好的方法(使用sql優化)將是:
創建您的類型:
CREATE TYPE dbo.IntTTV AS TABLE
( Id int )
您的身份證:
var ids = new List<int>
{
1,
2,
3,
}
創建一個架構:
var tableSchema = new List<SqlMetaData>(1)
{
new SqlMetaData("Id", SqlDbType.Int) // I think it's Int
}.ToArray();
在C#中創建表
var table = ids
.Select(i =>
{
var row = new SqlDataRecord(tableSchema);
row.SetInt32(0, i);
return row;
})
.ToList();
創建SQL參數
var parameter = new SqlParameter();
parameter.SqlDbType = SqlDbType.Structured;
parameter.ParameterName = "@Ids";
parameter.Value = table;
parameter.TypeName = "dbo.IntTTV";
var parameters = new SqlParameter[1]
{
parameter
};
稍微更改您的查詢(這只是一個示例:)
string query = "select mrd.CaseList from MasterReportData mrd"
+ " inner join @ids i on mrd.Id = i.id";
public static List<string> GetCaseList(string[] masterIdList)
{
List<string> list = new List<string>();
try
{
string query = "select CaseList from MasterReportData where ";
using (SqlConnection conn = new SqlConnection(connString))
{
int i = 0;
SqlCommand cmd = new SqlCommand(query, conn);
for(i = 0; i < masterIdList.Length; i++)
{
var parm = "@ID" + i;
cmd.Parameters.Add(new SqlParameter(parm, masterIdList[i]));
query += (i > 0 ? " OR " : "") + " Id = " + parm;
}
cmd.CommandText = query;
//cmd.Parameters.AddWithValue("masterId", ***);
conn.Open();
using (SqlDataReader reader = cmd.ExecuteReader())
{
while (reader.Read())
{
list.Add(reader[0].ToString());
}
}
}
}
catch (Exception e)
{
e.ToString();
}
return list;
}
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