MCOL-4044: Add oracle mode functions.

utils/funcexp/func_concat_oracle.cpp

@@ -0,0 +1,78 @@
+/* Copyright (C) 2021 MariaDB Corporation
+
+   This program is free software; you can redistribute it and/or
+   modify it under the terms of the GNU General Public License
+   as published by the Free Software Foundation; version 2 of
+   the License.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+   MA 02110-1301, USA. */
+
+#include <string>
+using namespace std;
+
+#include "functor_str.h"
+#include "functioncolumn.h"
+#include "utils_utf8.h"
+using namespace execplan;
+
+#include "rowgroup.h"
+using namespace rowgroup;
+
+#include "dataconvert.h"
+using namespace dataconvert;
+
+namespace funcexp
+{
+
+CalpontSystemCatalog::ColType Func_concat_oracle::operationType(FunctionParm& fp, CalpontSystemCatalog::ColType& resultType )
+{
+    // operation type is not used by this functor
+    return fp[0]->data()->resultType();
+}
+
+
+// Returns the string that results from concatenating the arguments.
+// concat_oracle() returns NULL all arguments are NULL.
+// single arguments null is replaced by "".
+//
+string Func_concat_oracle::getStrVal(Row& row,
+                              FunctionParm& parm,
+                              bool& isNull,
+                              CalpontSystemCatalog::ColType&)
+{
+	string ret;
+    string tmp;
+    stringValue(parm[0], row, isNull, ret);
+    // Oracle Mode should replace NULL with "" unless all values are NULL
+    if (isNull)
+    {
+        ret = "";
+        isNull = false;
+    }
+    // TODO: do a better job of cutting down the number re-allocations.
+    // look at Item_func_concat::realloc_result for ideas and use 
+    // std::string:resize() appropriatly.
+    for ( unsigned int id = 1 ; id < parm.size() ; id++)
+    {
+		stringValue(parm[id], row, isNull, tmp);
+	    if (isNull)
+	    {
+	        tmp = "";
+	        isNull = false;
+	    }
+        ret.append(tmp);
+    }
+
+    return ret;
+}
+
+} // namespace funcexp
+// vim:ts=4 sw=4: