我有以下代码:
Using cmd As SqlCommand = Connection.CreateCommand
cmd.CommandText = "UPDATE someTable SET Value = @Value"
cmd.CommandText &= " WHERE Id = @Id"
cmd.Parameters.AddWithValue("@Id", 1234)
cmd.Parameters.AddWithValue("@Value", "myValue")
cmd.ExecuteNonQuery
End Using
我想知道是否有任何方法来获得最终的SQL语句作为字符串，它应该看起来像这样:
UPDATE someTable SET Value = "myValue" WHERE Id = 1234
如果有人想知道我为什么要这么做
用于记录(失败的)语句 可以将其复制粘贴到企业管理器中进行测试
当前回答
sql命令查询将通过exec sp_executesql执行，所以这里有另一种方法来获取语句作为字符串(SqlCommand扩展方法):
public static string ToSqlStatement(this SqlCommand cmd)
{
return $@"EXECUTE sp_executesql N'{cmd.CommandText.Replace("'", "''")}'{cmd.Parameters.ToSqlParameters()}";
}
private static string ToSqlParameters(this SqlParameterCollection col)
{
if (col.Count == 0)
return string.Empty;
var parameters = new List<string>();
var parameterValues = new List<string>();
foreach (SqlParameter param in col)
{
parameters.Add($"{param.ParameterName}{param.ToSqlParameterType()}");
parameterValues.Add($"{param.ParameterName} = {param.ToSqlParameterValue()}");
}
return $",N\'{string.Join(",", parameters)}\',{string.Join(",", parameterValues)}";
}
private static object ToSqlParameterType(this SqlParameter param)
{
var paramDbType = param.SqlDbType.ToString().ToLower();
if (param.Precision != 0 && param.Scale != 0)
return $"{paramDbType}({param.Precision},{param.Scale})";
if (param.Precision != 0)
return $"{paramDbType}({param.Precision})";
switch (param.SqlDbType)
{
case SqlDbType.VarChar:
case SqlDbType.NVarChar:
string s = param.SqlValue?.ToString() ?? string.Empty;
return paramDbType + (s.Length > 0 ? $"({s.Length})" : string.Empty);
default:
return paramDbType;
}
}
private static string ToSqlParameterValue(this SqlParameter param)
{
switch (param.SqlDbType)
{
case SqlDbType.Char:
case SqlDbType.Date:
case SqlDbType.DateTime:
case SqlDbType.DateTime2:
case SqlDbType.DateTimeOffset:
case SqlDbType.NChar:
case SqlDbType.NText:
case SqlDbType.NVarChar:
case SqlDbType.Text:
case SqlDbType.Time:
case SqlDbType.VarChar:
case SqlDbType.Xml:
return $"\'{param.SqlValue.ToString().Replace("'", "''")}\'";
case SqlDbType.Bit:
return param.SqlValue.ToBooleanOrDefault() ? "1" : "0";
default:
return param.SqlValue.ToString().Replace("'", "''");
}
}
public static bool ToBooleanOrDefault(this object o, bool defaultValue = false)
{
if (o == null)
return defaultValue;
string value = o.ToString().ToLower();
switch (value)
{
case "yes":
case "true":
case "ok":
case "y":
return true;
case "no":
case "false":
case "n":
return false;
default:
bool b;
if (bool.TryParse(o.ToString(), out b))
return b;
break;
}
return defaultValue;
}
其他回答
为了记录日志，恐怕没有更好的方法了，只能自己构造字符串:
string query = cmd.CommandText;
foreach (SqlParameter p in cmd.Parameters)
{
query = query.Replace(p.ParameterName, p.Value.ToString());
}
这个方法是我自己写的。我用了布鲁诺·拉尼克的代码。也许它对某人有用。
public static string getQueryFromCommand(SqlCommand cmd)
{
StringBuilder CommandTxt = new StringBuilder();
CommandTxt.Append("DECLARE ");
List<string> paramlst = new List<string>();
foreach (SqlParameter parms in cmd.Parameters)
{
paramlst.Add(parms.ParameterName);
CommandTxt.Append(parms.ParameterName + " AS ");
CommandTxt.Append(parms.SqlDbType.ToString());
CommandTxt.Append(",");
}
if (CommandTxt.ToString().Substring(CommandTxt.Length-1, 1) == ",")
CommandTxt.Remove(CommandTxt.Length-1, 1);
CommandTxt.AppendLine();
int rownr = 0;
foreach (SqlParameter parms in cmd.Parameters)
{
string val = String.Empty;
if (parms.DbType.Equals(DbType.String) || parms.DbType.Equals(DbType.DateTime))
val = "'" + Convert.ToString(parms.Value).Replace(@"\", @"\\").Replace("'", @"\'") + "'";
if (parms.DbType.Equals(DbType.Int16) || parms.DbType.Equals(DbType.Int32) || parms.DbType.Equals(DbType.Int64) || parms.DbType.Equals(DbType.Decimal) || parms.DbType.Equals(DbType.Double))
val = Convert.ToString(parms.Value);
CommandTxt.AppendLine();
CommandTxt.Append("SET " + paramlst[rownr].ToString() + " = " + val.ToString());
rownr += 1;
}
CommandTxt.AppendLine();
CommandTxt.AppendLine();
CommandTxt.Append(cmd.CommandText);
return CommandTxt.ToString();
}
如果只是检查结果查询中的参数是如何格式化的，大多数DBMS将允许从无开始查询字面量。因此:
Using cmd As SqlCommand = Connection.CreateCommand
cmd.CommandText = "SELECT @Value"
cmd.Parameters.AddWithValue("@Value", "myValue")
Return cmd.ExecuteScalar
End Using
这样你就可以看到引号是否被加倍等等。
为我的解决方案使用了Flapper的部分代码，它返回整个SQL字符串，包括在MS SQL SMS中运行的参数值。
public string ParameterValueForSQL(SqlParameter sp)
{
string retval = "";
switch (sp.SqlDbType)
{
case SqlDbType.Char:
case SqlDbType.NChar:
case SqlDbType.NText:
case SqlDbType.NVarChar:
case SqlDbType.Text:
case SqlDbType.Time:
case SqlDbType.VarChar:
case SqlDbType.Xml:
case SqlDbType.Date:
case SqlDbType.DateTime:
case SqlDbType.DateTime2:
case SqlDbType.DateTimeOffset:
if (sp.Value == DBNull.Value)
{
retval = "NULL";
}
else
{
retval = "'" + sp.Value.ToString().Replace("'", "''") + "'";
}
break;
case SqlDbType.Bit:
if (sp.Value == DBNull.Value)
{
retval = "NULL";
}
else
{
retval = ((bool)sp.Value == false) ? "0" : "1";
}
break;
default:
if (sp.Value == DBNull.Value)
{
retval = "NULL";
}
else
{
retval = sp.Value.ToString().Replace("'", "''");
}
break;
}
return retval;
}
public string CommandAsSql(SqlCommand sc)
{
string sql = sc.CommandText;
sql = sql.Replace("\r\n", "").Replace("\r", "").Replace("\n", "");
sql = System.Text.RegularExpressions.Regex.Replace(sql, @"\s+", " ");
foreach (SqlParameter sp in sc.Parameters)
{
string spName = sp.ParameterName;
string spValue = ParameterValueForSQL(sp);
sql = sql.Replace(spName, spValue);
}
sql = sql.Replace("= NULL", "IS NULL");
sql = sql.Replace("!= NULL", "IS NOT NULL");
return sql;
}
从参数命令到非参数命令，可以修改
Using cmd As SqlCommand = Connection.CreateCommand
cmd.CommandText = "UPDATE someTable SET Value = @Value"
cmd.CommandText &= " WHERE Id = @Id"
cmd.Parameters.AddWithValue("@Id", 1234)
cmd.Parameters.AddWithValue("@Value", "myValue")
cmd.ExecuteNonQuery
End Using
To
Private sub Update( byval myID as Int32, byval myVal as String)
Using cmd As SqlCommand = Connection.CreateCommand
cmd.CommandText = "UPDATE someTable SET Value = '" & myVaL & "'" & _
" WHERE Id = " & myID
cmd.ExecuteNonQuery
End Using
End sub
