SELECT EMPLOYEE_ID, CONCAT(FIRST_NAME," ",LAST_NAME) AS EMPLOYEE_NAME, HIRE_DATE
FROM EMPLOYEES
我尝试运行上面的代码,并给我错误(无效的参数数量)以进行串联。我正在尝试在FIRST_NAME和LAST_NAME之间添加一个空格。
CONCAT()
函数中放入两个参数,并且在该函数中禁止使用双引号,而可以使用单引号。因此,根据您的情况,请尝试使用SELECT EMPLOYEE_ID, CONCAT(CONCAT(FIRST_NAME,' '),LAST_NAME) AS EMPLOYEE_NAME, HIRE_DATE
FROM EMPLOYEES
或管道作为连接运算符
SELECT EMPLOYEE_ID, FIRST_NAME||' '||LAST_NAME AS EMPLOYEE_NAME, HIRE_DATE
FROM EMPLOYEES
SELECT EMPLOYEE_ID, FIRST_NAME||' '||LAST_NAME AS EMPLOYEE_NAME, HIRE_DATE
FROM EMPLOYEES;