Implement Prepare for stored procedures. Fixes #742

Author: bgrainger

docs/content/tutorials/migrating-from-connector-net.md

@@ -216,3 +216,4 @@ The following bugs in Connector/NET are fixed by switching to MySqlConnector. (~
 * [#97872](https://bugs.mysql.com/bug.php?id=97872): `KeepAlive` in connection string throws exception on .NET Core
 * [#98322](https://bugs.mysql.com/bug.php?id=98322): `new MySqlConnection(null)` throws `NullReferenceException`
 * [#99091](https://bugs.mysql.com/bug.php?id=99091): Unexpected return value getting integer for `TINYINT(1)` column
+* [#99793](https://bugs.mysql.com/bug.php?id=99793): Prepared stored procedure command doesn't verify parameter types

src/MySqlConnector/Core/ServerSession.cs

@@ -140,7 +140,36 @@ public async Task PrepareAsync(IMySqlCommand command, IOBehavior ioBehavior, Can
 			// caller has validated this already
 			var commandText = command.CommandText!;
 
-			var statementPreparer = new StatementPreparer(commandText, command.RawParameters, command.CreateStatementPreparerOptions());
+			// for a stored procedure, the statement to be prepared is "CALL commandText(?,?,?,...);"
+			string commandToPrepare;
+			if (command.CommandType == CommandType.StoredProcedure)
+			{
+				var cachedProcedure = await command.Connection!.GetCachedProcedure(commandText, revalidateMissing: false, ioBehavior, cancellationToken).ConfigureAwait(false);
+				if (cachedProcedure is null)
+				{
+					var name = NormalizedSchema.MustNormalize(command.CommandText!, command.Connection.Database);
+					throw new MySqlException("Procedure or function '{0}' cannot be found in database '{1}'.".FormatInvariant(name.Component, name.Schema));
+				}
+
+				var parameterCount = cachedProcedure.Parameters.Count;
+				var callStatement = new StringBuilder("CALL ", commandText.Length + 8 + parameterCount * 2);
+				callStatement.Append(commandText);
+				callStatement.Append('(');
+				for (int i = 0; i < parameterCount; i++)
+					callStatement.Append("?,");
+				if (parameterCount == 0)
+					callStatement.Append(')');
+				else
+					callStatement[callStatement.Length - 1] = ')';
+				callStatement.Append(';');
+				commandToPrepare = callStatement.ToString();
+			}
+			else
+			{
+				commandToPrepare = commandText;
+			}
+
+			var statementPreparer = new StatementPreparer(commandToPrepare, command.RawParameters, command.CreateStatementPreparerOptions());
 			var parsedStatements = statementPreparer.SplitStatements();
 
 			var columnsAndParameters = new ResizableArray<byte>();

src/MySqlConnector/MySql.Data.MySqlClient/MySqlCommand.cs

@@ -128,9 +128,9 @@ private bool NeedsPrepare(out Exception? exception)
 			if (exception is object || Connection!.IgnorePrepare)
 				return false;
 
-			if (CommandType != CommandType.Text)
+			if (CommandType != CommandType.StoredProcedure && CommandType != CommandType.Text)
 			{
-				exception = new NotSupportedException("Only CommandType.Text is currently supported by MySqlCommand.Prepare");
+				exception = new NotSupportedException("Only CommandType.Text and CommandType.StoredProcedure is currently supported by MySqlCommand.Prepare");
 				return false;
 			}