implement of any value expr in mysql mode

src/sql/engine/expr/ob_expr_any_value.cpp

@@ -0,0 +1,67 @@
+/*
+ * Copyright 2014-2021 Alibaba Inc. All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ * ob_expr_any_value.cpp is for any_value function
+ *
+ * Date: 2021/7/9
+ *
+ * Authors:
+ *     ailing.lcq<ailing.lcq@alibaba-inc.com>
+ *
+ */
+
+#include "sql/engine/expr/ob_expr_any_value.h"
+
+using namespace oceanbase::common;
+
+namespace oceanbase {
+namespace sql {
+
+ObExprAnyValue::ObExprAnyValue(ObIAllocator &alloc)
+    : ObFuncExprOperator(alloc, T_FUN_SYS_ANY_VALUE, N_ANY_VAL, 1, NOT_ROW_DIMENSION)
+{}
+
+ObExprAnyValue::~ObExprAnyValue()
+{}
+
+int ObExprAnyValue::calc_result_type1(ObExprResType &type, ObExprResType &arg, common::ObExprTypeCtx &) const
+{
+  int ret = OB_SUCCESS;
+  type = arg;
+  return ret;
+}
+
+int ObExprAnyValue::calc_result1(common::ObObj &result, const common::ObObj &arg, common::ObExprCtx &expr_ctx) const
+{
+  UNUSED(expr_ctx);
+  int ret = OB_SUCCESS;
+  result = arg;
+  return ret;
+}
+
+int ObExprAnyValue::cg_expr(ObExprCGCtx &expr_cg_ctx, const ObRawExpr &raw_expr, ObExpr &rt_expr) const
+{
+  UNUSED(raw_expr);
+  UNUSED(expr_cg_ctx);
+  rt_expr.eval_func_ = ObExprAnyValue::eval_any_value;
+  return OB_SUCCESS;
+}
+
+int ObExprAnyValue::eval_any_value(const ObExpr &expr, ObEvalCtx &ctx, ObDatum &expr_datum)
+{
+  int ret = OB_SUCCESS;
+  ObDatum *arg = NULL;
+  if (OB_FAIL(expr.eval_param_value(ctx, arg))) {
+    SERVER_LOG(WARN, "expr evaluate parameter failed", K(ret));
+  } else {
+    expr_datum.set_datum(*arg);
+  }
+  return ret;
+}
+
+}  // namespace sql
+}  // namespace oceanbase