if 語句中的 SqlParameter

[wendy_fw]

string str = "select colA,colB,colC from tableA ";
if (condition)
str += "and colD in (@role)";

SqlParameter[] param = {
new SqlParameter ("@role",SqlDbType.NVarChar,300)};
param[0].Value = "'a','b'";

當執行ExecuteReader 時為什麼 SqlDataReader.Read()為false 啊.
(導出查詢語句沒有什麼問題.)

謝謝.

[cppfaq]

SQL 拼的有问题

SqlCommand command = new SqlCommand();
        string str = "select colA,colB,colC from tableA ";
        if (condition)
        {
            str += "where colD in (@role)";

            SqlParameter param = new SqlParameter ("@role",SqlDbType.NVarChar,300);
            command.Parameters.Add(param).Value = "'a','b'";
        }
        command.CommandText = str;

[xz_xq]

楼上正解

[mqc507]

逗··· 真逗 ···· 真的很逗 ····

[Jcomet]

少了where关键字！

[wuyq11]

string str = "select colA,colB,colC from tableA where 1=1";
if (condition)
str += "and colD in (@role)";

[xsm545]

少了where关键字！顶

[Adechen]

明显是sql 有问题,
1楼正解

[小时候很凶_tusiji]

string str = "select colA,colB,colC from tableA where 1=1 ";
if (condition)
str += "and colD in (@role)";

SqlParameter[] param = {
new SqlParameter ("@role",SqlDbType.NVarChar,300)};
param[0].Value = "'a','b'";


这样你下面如果还有条件的话。

[wendy_fw]

string str = "select colA,colB,colC from tableA ";
if (condition)
str += "where colD in (@role)";

SqlParameter[] param = {
new SqlParameter ("@role",SqlDbType.NVarChar,300)};
param[0].Value = "'a','b'";

不好意思, 是我打錯了,應該是where的

[wendy_fw]

string str = "select colA,colB,colC from tableA where colA='xxx'";
if (condition)
str += " and colD in (@role)";

SqlParameter[] param = {
new SqlParameter ("@role",SqlDbType.NVarChar,300)};
param[0].Value = "'a','b'";

[crazyminds110]

查你数据库中的数据是否有符合你要查询的结果
如果没有语法错误，可能你的错误出现在你的查询条件上
检查

[wendy_fw]

當我直接這樣寫的時候,dr.Read()就是True 哦,
一旦想通過參數去執行,dr.Read()就是False.
真的不知道怎麼回事啊

 string str = "select colA,colB,colC from tableA where colA='xxx'";
        if (condition)
            str += " and colD in ('a','b')";

        //SqlParameter[] param = { 
        //    new SqlParameter ("@role",SqlDbType.NVarChar,300)};
        //param[0].Value = "'a','b'";
SqlDataReader dr = SQLUtility.ExecuteReader(SQLUtility.ConnMenu, CommandType.Text, str, parm);

        List<RDTreeNode> treeNode = new List<RDTreeNode>(); 
        while (dr.Read())
        {
... ...

[wendy_fw]

我自己搞定了. 換了種寫法:

if (condition)
  string str = "select colA,colB,colC from tableA where colA='xxx' and colD in (@role)";