未使用 WHERE 子句中的绑定变量执行本机动态 SQL DDL 语句

Question

我正在练习动态 SQL 和过程，以便为每周、每天和每月的仪表板实现一些脚本。这些仪表板要求我们创建表，因此我决定坚持使用动态 SQL。 在练习这些时，我遇到了一些错误，为了模拟错误，我创建了以下表格并复制了程序。

1。生成 EMP 表

CREATE TABLE EMP
(EMPNO NUMERIC(4) NOT NULL,
ENAME VARCHAR(10),
JOB VARCHAR(9),
MGR NUMERIC(4),
HIREDATE DATE,
SAL NUMERIC(7, 2),
COMM NUMERIC(7, 2),
DEPTNO NUMERIC(2));

INSERT INTO EMP VALUES
(7369, 'SMITH', 'CLERK', 7902, '17-DEC-1980', 800, NULL, 20);
INSERT INTO EMP VALUES
(7499, 'ALLEN', 'SALESMAN', 7698, '20-FEB-1981', 1600, 300, 30);
INSERT INTO EMP VALUES
(7521, 'WARD', 'SALESMAN', 7698, '22-FEB-1981', 1250, 500, 30);
INSERT INTO EMP VALUES
(7566, 'JONES', 'MANAGER', 7839, '2-APR-1981', 2975, NULL, 20);
INSERT INTO EMP VALUES
(7654, 'MARTIN', 'SALESMAN', 7698, '28-SEP-1981', 1250, 1400, 30);
INSERT INTO EMP VALUES
(7698, 'BLAKE', 'MANAGER', 7839, '1-MAY-1981', 2850, NULL, 30);
INSERT INTO EMP VALUES
(7782, 'CLARK', 'MANAGER', 7839, '9-JUN-1981', 2450, NULL, 10);
INSERT INTO EMP VALUES
(7788, 'SCOTT', 'ANALYST', 7566, '09-DEC-1982', 3000, NULL, 20);
INSERT INTO EMP VALUES
(7839, 'KING', 'PRESIDENT', NULL, '17-NOV-1981', 5000, NULL, 10);
INSERT INTO EMP VALUES
(7844, 'TURNER', 'SALESMAN', 7698, '8-SEP-1981', 1500, 0, 30);
INSERT INTO EMP VALUES
(7876, 'ADAMS', 'CLERK', 7788, '12-JAN-1983', 1100, NULL, 20);
INSERT INTO EMP VALUES
(7900, 'JAMES', 'CLERK', 7698, '3-DEC-1981', 950, NULL, 30);
INSERT INTO EMP VALUES
(7902, 'FORD', 'ANALYST', 7566, '3-DEC-1981', 3000, NULL, 20);
INSERT INTO EMP VALUES
(7934, 'MILLER', 'CLERK', 7782, '23-JAN-1982', 1300, NULL, 10);

2。生成 EmpSalary 表

CREATE TABLE empSalary
(ename varchar(20),
salary number
);


INSERT INTO empSalary VALUES ('SMITH', 2000);
INSERT INTO empSalary VALUES ('WARD', 300);
COMMIT;

以下过程很好：

---- 制定程序 - 尝试 1

CREATE OR REPLACE PROCEDURE getData(dataType IN VARCHAR2)
IS
  newTbl VARCHAR2(20);
  sqlQuery  VARCHAR2(100);
  empName VARCHAR2(20) := 'SMITH';
BEGIN
  IF dataType = 'Weekly' THEN
      newTbl := 'empTblWeekly'||TO_CHAR(SYSDATE, 'ddmon');
      sqlQuery := 'CREATE TABLE '||newTbl||' as SELECT * FROM emp';
      EXECUTE IMMEDIATE sqlQuery;
  ELSIF dataType = 'Daily' THEN
      newTbl := 'empTblDaily'||TO_CHAR(SYSDATE, 'ddmon');
      sqlQuery := 'CREATE TABLE '||newTbl||' as SELECT * FROM empSalary';
      EXECUTE IMMEDIATE sqlQuery;
  ELSIF dataType = 'Monthly' THEN
      newTbl := 'empTblMonthly'||TO_CHAR(SYSDATE, 'ddmon');
      sqlQuery := 'CREATE TABLE '||newTbl||' as SELECT * FROM emp WHERE ENAME = ''SMITH''';
      EXECUTE IMMEDIATE sqlQuery;
  END IF;
EXCEPTION
  WHEN NO_DATA_FOUND THEN
  DBMS_OUTPUT.PUT_LINE('No data found!');
  COMMIT;
END;

BEGIN
getData('Monthly');
END;

SELECT *
FROM empTblMonthly21Feb;

以下 2 个公式返回错误：

---- Formulating a Procedure  - Try 2

CREATE OR REPLACE PROCEDURE getData(dataType IN VARCHAR2)
IS
  newTbl VARCHAR2(20);
  sqlQuery  VARCHAR2(100);
  empName VARCHAR2(20) := 'SMITH';
BEGIN
  IF dataType = 'Weekly' THEN
      newTbl := 'empTblWeekly'||TO_CHAR(SYSDATE, 'ddmon');
      sqlQuery := 'CREATE TABLE '||newTbl||' as SELECT * FROM emp';
      EXECUTE IMMEDIATE sqlQuery;
  ELSIF dataType = 'Daily' THEN
      newTbl := 'empTblDaily'||TO_CHAR(SYSDATE, 'ddmon');
      sqlQuery := 'CREATE TABLE '||newTbl||' as SELECT * FROM empSalary';
      EXECUTE IMMEDIATE sqlQuery;
  ELSIF dataType = 'Monthly' THEN
      newTbl := 'empTblMonthly'||TO_CHAR(SYSDATE, 'ddmon');
      sqlQuery := 'CREATE TABLE '||newTbl||' as SELECT * FROM emp WHERE ENAME = :empName';
      EXECUTE IMMEDIATE sqlQuery USING empName;
  END IF;
EXCEPTION
  WHEN NO_DATA_FOUND THEN
  DBMS_OUTPUT.PUT_LINE('No data found!');
  COMMIT;
END;

    BEGIN
    getData('Monthly');
    END;

    SELECT *
    FROM empTblMonthly21Feb;

---ORA-01027: bind variables not allowed for data definition operations ORA-06512: at "SYS.GETDATA", line 18 ORA-06512: at line 2


---- Formulating a Procedure  - Try 3

CREATE OR REPLACE PROCEDURE getData(dataType IN VARCHAR2)
IS
  newTbl VARCHAR2(20);
  sqlQuery  VARCHAR2(100);
  empName VARCHAR2(20) := 'SMITH';
BEGIN
  IF dataType = 'Weekly' THEN
      newTbl := 'empTblWeekly'||TO_CHAR(SYSDATE, 'ddmon');
      sqlQuery := 'CREATE TABLE '||newTbl||' as SELECT * FROM emp';
      EXECUTE IMMEDIATE sqlQuery;
  ELSIF dataType = 'Daily' THEN
      newTbl := 'empTblDaily'||TO_CHAR(SYSDATE, 'ddmon');
      sqlQuery := 'CREATE TABLE '||newTbl||' as SELECT * FROM empSalary';
      EXECUTE IMMEDIATE sqlQuery;
  ELSIF dataType = 'Monthly' THEN
      newTbl := 'empTblMonthly'||TO_CHAR(SYSDATE, 'ddmon');
      sqlQuery := 'CREATE TABLE '||newTbl||' as SELECT * FROM emp WHERE ENAME ='||empName;
      EXECUTE IMMEDIATE sqlQuery;
  END IF;
EXCEPTION
  WHEN NO_DATA_FOUND THEN
  DBMS_OUTPUT.PUT_LINE('No data found!');
  COMMIT;
END;

    BEGIN
    getData('Monthly');
    END;

    SELECT *
    FROM empTblMonthly21Feb;

---ORA-00904: "SMITH": invalid identifier ORA-06512: at "SYS.GETDATA", line 18 ORA-06512: at line 2

但我无法理解为什么会出现错误，因为在第二次尝试中，我没有使用绑定变量作为表名，而在第三次尝试中，我只是连接了一个变量...

感谢您的帮助...

Answer 1

您的第三次尝试会成功，但您忘记了 sql 语句中的单引号（围绕 ename 变量）。尝试类似：

declare
  l_tabname varchar2(100) := 'MY_TAB1';
  l_name varchar2(100) := 'SMITH';
  l_sql varchar2(1000);
begin
  l_sql := 'create table ' || l_tabname || ' as select * from emp where ename = ''' || l_name || '''';
  execute immediate l_sql;
end;

没有使用绑定变量，但它仍然使用变量创建表。