support json type

src/sql/engine/expr/ob_expr_json_pretty.h

@@ -0,0 +1,49 @@
+/**
+ * Copyright (c) 2021 OceanBase
+ * OceanBase CE is licensed under Mulan PubL v2.
+ * You can use this software according to the terms and conditions of the Mulan PubL v2.
+ * You may obtain a copy of Mulan PubL v2 at:
+ *          http://license.coscl.org.cn/MulanPubL-2.0
+ * THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND,
+ * EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT,
+ * MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
+ * See the Mulan PubL v2 for more details.
+ */
+
+// This file is for define of func json_pretty
+#ifndef OCEANBASE_SQL_OB_EXPR_JSON_PRETTY_H_
+#define OCEANBASE_SQL_OB_EXPR_JSON_PRETTY_H_
+
+#include "sql/engine/expr/ob_expr_operator.h"
+#include "lib/json_type/ob_json_common.h"
+
+using namespace oceanbase::common;
+
+namespace oceanbase
+{
+namespace sql
+{
+class ObExprJsonPretty : public ObFuncExprOperator
+{
+public:
+  explicit ObExprJsonPretty(common::ObIAllocator &alloc);
+  virtual ~ObExprJsonPretty();
+  template <typename T>
+  static int calc(const T &data, ObObjType type, ObCollationType cs_type,
+                  ObIAllocator *allocator, ObJsonBuffer &j_buf, bool &is_null);
+  int calc_result1(common::ObObj &result, const common::ObObj &obj, common::ObExprCtx &expr_ctx) const override;
+  int calc_result_type1(ObExprResType &type,
+                        ObExprResType &type1,
+                        common::ObExprTypeCtx &type_ctx) const override;
+  
+  static int eval_json_pretty(const ObExpr &expr, ObEvalCtx &ctx, ObDatum &res);
+  
+  virtual int cg_expr(ObExprCGCtx &expr_cg_ctx, const ObRawExpr &raw_expr,
+                    ObExpr &rt_expr) const override;
+private:
+    DISALLOW_COPY_AND_ASSIGN(ObExprJsonPretty);
+};
+
+} // sql
+} // oceanbase
+#endif // OCEANBASE_SQL_OB_EXPR_JSON_PRETTY_H_