oracle自定义存储过程删除表(无论表是否存在)和检测表是否存在

Z时代
2024-01-10
分类：综合

database

oracle删除表，如果表不存在，就报错，在跑大型脚本（脚本长且耗时的时候）比较麻烦，一般希望的是点开始然后脚本运行到结束，不可能一直盯着屏幕等弹出提示手工点掉，mysql就很好有drop table if not exist功能

CREATE OR REPLACE PROCEDURE p_drop_table_if_exist(p_vc2_tbl_name  IN all_tables.table_name%TYPE,
                                    p_vc2_tbl_owner IN all_tables.owner%TYPE DEFAULT USER) IS
    v_num_tbl_count NUMBER(4);
    v_vc2_sql_stmt  VARCHAR2(1000);
  BEGIN
    -- Check if table already exists
    p_chk_table_exist(p_vc2_tbl_name, p_vc2_tbl_owner, v_num_tbl_count);
    IF (v_num_tbl_count != 0) THEN
      -- Table already exists and must be dropped
      v_vc2_sql_stmt := "DROP TABLE " || CASE
                          WHEN p_vc2_tbl_owner IS NOT NULL THEN
                           p_vc2_tbl_owner || "."
                        END || p_vc2_tbl_name || " purge"
                        ;
      --dbms_output.put_line(v_vc2_sql_stmt);
      EXECUTE IMMEDIATE v_vc2_sql_stmt;
    END IF;
  END;
CREATE OR REPLACE PROCEDURE p_chk_table_exist(p_vc2_tbl_name  IN all_tables.table_name%TYPE,
                                p_vc2_tbl_owner IN all_tables.owner%TYPE DEFAULT USER,
                                p_num_tbl_count OUT NUMBER -- 1 if table exists, 0 if it doesn"t
                                ) IS
    v_vc2_tbl_name all_tables.table_name%TYPE := UPPER(p_vc2_tbl_name);
  BEGIN
    IF p_vc2_tbl_owner IS NOT NULL THEN
      SELECT COUNT(1)
        INTO p_num_tbl_count
        FROM all_tables
       WHERE table_name = v_vc2_tbl_name
         AND owner = UPPER(p_vc2_tbl_owner);
    ELSE
      SELECT COUNT(1)
        INTO p_num_tbl_count
        FROM user_tables
       WHERE table_name = v_vc2_tbl_name;
    END IF;
  END p_chk_table_exist;