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src/sql/engine/expr/ob_expr_concat_ws.h

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+/**
+ * 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.
+ */
+
+#ifndef SRC_SQL_ENGINE_EXPR_OB_EXPR_CONCAT_WS_H_
+#define SRC_SQL_ENGINE_EXPR_OB_EXPR_CONCAT_WS_H_
+#include "sql/engine/expr/ob_expr_operator.h"
+namespace oceanbase {
+namespace sql {
+// stands for Concatenate With Separator and is a special form of CONCAT()
+class ObExprConcatWs : public ObStringExprOperator {
+  public:
+  ObExprConcatWs();
+  explicit ObExprConcatWs(common::ObIAllocator& alloc);
+  virtual ~ObExprConcatWs();
+  virtual int calc_result_typeN(
+      ObExprResType& type, ObExprResType* types, int64_t param_num, common::ObExprTypeCtx& type_ctx) const;
+  virtual int calc_resultN(
+      common::ObObj& result, const common::ObObj* objs, int64_t param_num, common::ObExprCtx& expr_ctx) const;
+  // connect two strings by separator
+  static int concat_ws(
+      const common::ObString obj1, const common::ObString obj2, const int64_t buf_len, char** string_buf, int64_t& pos);
+  // connect any strings by separator
+  static int calc(common::ObObj& result, const common::ObString& sep_str, const common::ObObj* objs,
+      const int64_t param_num, common::ObExprCtx& expr_ctx);
+  virtual int cg_expr(ObExprCGCtx& expr_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;
+  static int calc_concat_ws_expr(const ObExpr& expr, ObEvalCtx& ctx, ObDatum& res);
+  static int calc(const common::ObString& sep_str, const common::ObIArray<common::ObString>& words,
+      common::ObIAllocator& alloc, common::ObString& res_str);
+
+  private:
+  // disallow copy
+  DISALLOW_COPY_AND_ASSIGN(ObExprConcatWs);
+};
+
+}  // namespace sql
+}  // namespace oceanbase
+
+#endif /* SRC_SQL_ENGINE_EXPR_OB_EXPR_CONCAT_WS_H_ */