From .NET can I get the full SQL string generated by a SqlCommand object (with SQL Parameters)?

Question

From the .NET environment can I get access to the full SQL string that is generated by a SqlCommand object?

Note: The full SQL string shows up in Intellisense hover, in VisualStudio, while in debug mode.

I'm willing to use reflection techniques if I must. I'm sure somebody here knows a way to get at it.

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Update 1:
I'm calling a stored procedure having parameters with cmd.CommandType = CommandType.StoredProcedure and am trying to acquire the full SQL generated and run. I wonder if the cmd.Prepare() method might not prove useful in this circumstance, if it might store the full string in a state field or something like that.

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Update 2:

In light of answers below (and referenced) that indicate no complete SQL string is generated internally during preparation or execution, I did a bit of poking around using .NET Reflector. Even the internal connection classes seem to pass objects rather than boiling them down to strings, for example:

internal abstract void AddPreparedCommand(SqlCommand cmd);
Declaring Type: System.Data.SqlClient.SqlInternalConnection
Assembly: System.Data, Version=2.0.0.0

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In general, thanks to everybody for the level of detail you got into to prove what can be done and show what's actually happening. Much appreciated. I like thorough explanations; they add surety and lend credence to the answers.

Latonya

Are you generating in-line SQL or calling a stored procedure? Either way, are you adding parameters? – Hint

I am adding parameters. I've realized through seeing some of the initial answers that it may be a different answer depending on whether I have parameters or not. I'll leave this question as is and open another later if I see the SQLParameter issue hasn't been addressed. – Latonya

I decided to add an update to the question and provide additional information that I've learned might make a different to answers. – Latonya

I have tried this many times -- to capture the SQL for testing and/or for logging. You can get an approximation of the SQL from your app, but the command is never put together into a single SQL statement until it gets to the database engine. So, if you have access to Profiler or a similar tool on the database side, you can examine from there. Otherwise, I'm afraid you're stuck with an approximation. – Hint

Actually, even in the database engine, the SQL statement isn't "put together" in any form, except with the parameters as a separate entity. The code is compiled as a parameterized piece of code, with query hints detailing the standard parameter values that would be used, and then afterwords is "called" with the specified parameters. As such, there is no way you will get hold of a SQL statement with the parameter values injected into it, except if you build it yourself. – Livengood

It's worth looking at TdsExecuteRPC in github.com/Microsoft/referencesource/blob/master/System.Data/… – Sacrarium

Possible duplicate of How to debug parameterized SQL query – Instigation

Answer 1

A simple loop replacing all the parameter names with their values will provide you with something similar to what the end result is, but there are several problems.

1. Since the SQL is never actually rebuilt using the parameter values, things like newlines and quotes don't need to be considered
2. Parameter names in comments are never actually processed for their value, but left as-is

With those in place, and taking into account parameter names that starts with the same characters, like @NAME and @NAME_FULL, we can replace all the parameter names with the value that would be in the place of that parameter:

string query = cmd.CommandText;
foreach (SqlParameter p in cmd.Parameters.OrderByDescending(p => p.ParameterName.Length))
{
    query = query.Replace(p.ParameterName, p.Value.ToString());
}

there is one problem left with this, however, and that is if a parameter is a string, then the SQL that initially looks like this:

SELECT * FROM yourtable WHERE table_code = @CODE

will look like this:

SELECT * FROM yourtable WHERE table_code = SOME CODE WITH SPACES

This is clearly not legal SQL, so we need to account for some parameter-types as well:

DbType[] quotedParameterTypes = new DbType[] {
    DbType.AnsiString, DbType.Date,
    DbType.DateTime, DbType.Guid, DbType.String,
    DbType.AnsiStringFixedLength, DbType.StringFixedLength
};
string query = cmd.CommandText;

var arrParams = new SqlParameter[cmd.Parameters.Count];
cmd.Parameters.CopyTo(arrParams, 0);

foreach (SqlParameter p in arrParams.OrderByDescending(p => p.ParameterName.Length))
{
    string value = p.Value.ToString();
    if (quotedParameterTypes.Contains(p.DbType))
        value = "'" + value + "'";
    query = query.Replace(p.ParameterName, value);
}

Jamboree

-1. This is not anything like what gets sent to the server, and would result in invalid SQL anyhow. – Usn

I used debugging as an example of when I see the SQL, so I don't need anything for debugging. What I'm looking for is a string with the SQL that's actually generated and run on the db. You're right the parameter collection can be reversed but since I created the parameter collection I already know what's in it. – Latonya

This is as close as you're going to get to what the SQL will look like as Adam said, ADO.NET executes the sql in a different way then what you send, so what you send and what gets executed could be different. – Jamboree

I realize that, this is just as close as I could get to what he would want since he wanted to look at it from C#. – Jamboree

@Jesus: You're right. Your answer has taken on new context to me in light of details as they have come out in this thread. I had assumed there must be a string stored internally, somewhere, bu it looks like this may not be the case because of how it really works. – Latonya

Yeah, I was actually trying to be helpful and give you something you could use but I guess apparently that's not good enough for others. – Jamboree

@Jesus, it is probably still not complete, but I don't think it can get any closer to "the actual SQL being executed", except if you (that is, the OP), writes a full SQL parser and rewrites this with 100% working SQL. – Livengood

@Lasse, It really depends on what the OP wants, if he wants to make sure his SQL statements are what he really wants them to be then this should be fine, but if he really needs the EXACT SQL that is executing he will have to work a bit harder, personally I never had too many issues with that first snippet of code I posted, I usually use that to make sure that my formatting is OK. – Jamboree

OrderByDescending is not in use – Avan

Answer 2

There have been a couple of similar questions here.

The most compelling answer was provided to this question: How to get the generated SQL-Statment from a SqlCommand-Object?

and the answer was:

You can't, because it does not generate any SQL.

The parameterized query (the one in CommandText) is sent to the SQL Server as the equivalent of a prepared statement. When you execute the command, the parameters and the query text are treated separately. At no point in time a complete SQL string is generated.

You can use SQL Profiler to take a look behind the scenes.

Hint

Answer 3

The CommandText property (or calling ToString()) on your command will give you all of the SQL, with a small exception. It will definitely give you anything you see in the debugger. Note that this won't give you parameter values, but it will give you the actual command.

The only caveat is that when CommandType is Text, the ADO.NET framework will often (in fact, almost always) use sp_executesql to execute the command rather than executing the command directly against the connection. In that sense, it's not possible to obtain the exact SQL that gets executed.

Usn

So what exactly are you saying? You will get what is going to be shown, except in the cases that you won't? – Livengood

@Lasse V: Adam's answer was added before I edited the question and provided additional detail about SQL Parameters being used in my query. – Latonya

@Lasse: I'm saying that neither 'ToString()' nor 'CommandText' will automatically present a string representation of the parameter values, in case that was part of what the OP was looking for. – Usn

This is wrong! Calling ToString() on the SQLCommand object just gives you the qualified class name -- useless. – Hunger

Answer 4

I haven't tried this, but you may be able to use Capture Mode if you are willing to use SMO:

http://msdn.microsoft.com/en-us/library/ms162182(v=sql.120).aspx

Bluebonnet

Answer 5

I like Jesus Ramos answer, but I needed support for output parameters. (I also used a string builder to generate the content.)

Declare Parameter for output parameters

 foreach (SqlParameter p in arrParams.Where(x => x.Direction == ParameterDirection.Output || x.Direction == ParameterDirection.InputOutput))
    {
        // todo : I only needed a couple of types supported, you could add addition types
        string dbtype = string.Empty;
        switch (p.DbType)
        {
            case DbType.Guid:
                dbtype = "uniqueidentifier";
                break;
            case DbType.Int16:
            case DbType.Int64:
            case DbType.Int32:
                dbtype = "int";
                break;
            case DbType.String:
                dbtype = "varchar(max)";
                break;
        }

        query.Append(string.Format(" Declare {0}_ {1}\n", p.ParameterName, dbtype));
    }

Build Main Parameter Area

foreach (SqlParameter p in arrParams)
    {
        bool isLast = p == last;
        string value = p.Value.ToString();
        if (quotedParameterTypes.Contains(p.DbType))
            value = "'" + value + "'";
        if (p.Direction == ParameterDirection.InputOutput || p.Direction == ParameterDirection.Output)
        {
            query.Append(string.Format("{0} = {0}_ out{2}\n", p.ParameterName, value, isLast ? "" : ","));
        }
        else
        {
            query.Append(string.Format("{0} = {1}{2}\n", p.ParameterName, value, isLast ? "" : ","));
        }
    }

List Output Parameter results

foreach (SqlParameter p in arrParams.Where(x => x.Direction == ParameterDirection.Output || x.Direction == ParameterDirection.InputOutput))
    {
        query.Append(string.Format(" select {0}_ {1}\n", p.ParameterName, p.ParameterName.Substring(1)));
    }

Full Code:

        public static string GetProcedureDebugInformation(SqlCommand cmd, [System.Runtime.CompilerServices.CallerMemberName] string caller = null, [System.Runtime.CompilerServices.CallerFilePath] string filePath = null, [System.Runtime.CompilerServices.CallerLineNumber] int? lineNumber = null)
    {
        // Collection of parameters that should use quotes
        DbType[] quotedParameterTypes = new DbType[] {
            DbType.AnsiString, DbType.Date,
            DbType.DateTime, DbType.Guid, DbType.String,
            DbType.AnsiStringFixedLength, DbType.StringFixedLength
        };

        // String builder to contain generated string
        StringBuilder query = new StringBuilder();

        // Build some debugging information using free compiler information
        query.Append(filePath != null ? filePath : ""
        + (lineNumber.HasValue ? lineNumber.Value.ToString() : "")
        + (lineNumber.HasValue || !string.IsNullOrWhiteSpace(filePath) ? "\n\n" : ""));
        query.Append("\n\n");

        var arrParams = new SqlParameter[cmd.Parameters.Count];
        cmd.Parameters.CopyTo(arrParams, 0);

        // Declare Parameter for output parameters
        foreach (SqlParameter p in arrParams.Where(x => x.Direction == ParameterDirection.Output || x.Direction == ParameterDirection.InputOutput))
        {
            // todo : I only needed a couple of types supported, you could add addition types
            string dbtype = string.Empty;
            switch (p.DbType)
            {
                case DbType.Guid:
                    dbtype = "uniqueidentifier";
                    break;
                case DbType.Int16:
                case DbType.Int64:
                case DbType.Int32:
                    dbtype = "int";
                    break;
                case DbType.String:
                    dbtype = "varchar(max)";
                    break;
            }

            query.Append(string.Format(" Declare {0}_ {1}\n", p.ParameterName, dbtype));
        }

        // Set Exec Text
        query.Append(string.Format("\n exec {0}\n", cmd.CommandText));
        var last = arrParams.LastOrDefault();

        //Build Main Parameter Area
        foreach (SqlParameter p in arrParams.OrderByDescending(p => p.ParameterName.Length))
        {
            bool isLast = p == last;
            string value = p.Value.ToString();
            if (quotedParameterTypes.Contains(p.DbType))
                value = "'" + value + "'";
            if (p.Direction == ParameterDirection.InputOutput || p.Direction == ParameterDirection.Output)
            {
                query.Append(string.Format("{0} = {0}_ out{2}\n", p.ParameterName, value, isLast ? "" : ","));
            }
            else
            {
                query.Append(string.Format("{0} = {1}{2}\n", p.ParameterName, value, isLast ? "" : ","));
            }
        }

        // List Output Parameter results
        foreach (SqlParameter p in arrParams.Where(x => x.Direction == ParameterDirection.Output || x.Direction == ParameterDirection.InputOutput))
        {
            query.Append(string.Format(" select {0}_ {1}\n", p.ParameterName, p.ParameterName.Substring(1)));
        }

        return query.ToString();
    }

Nolde