聚集函数
聚集函数之间不支持嵌套调用。
ARRAY_AGG
语法：
ARRAY_AGG(expr)功能：将输入的值expr组成一个数组。支持分组聚集成数组。
注意：入参expr的的数据类型不能是数组、BINARY、VARBINARY、CLOB、BLOB、CURSOR，RAW，IMAGE。
示例：将test表的F2字段的值聚集成一个数组。
--删除表TEST。 DROP TABLE IF EXISTS TEST;--创建表TEST。 CREATE TABLE test ( f1 INTEGER, f2 INTEGER );--插入记录。 INSERT INTO test VALUES (1,1), (1,2), (1,3), (2, 100), (2,200), (2, 300), (3, 500), (3,600);--普通查询。 SELECT array_agg(f2) FROM test; ARRAY_AGG(F2) ---------------------------------------------------------------- {1,2,3,100,200,300,500,600}--分组查询按照分组字段聚集。 SELECT array_agg(f2) FROM test GROUP BY f1; ARRAY_AGG(F2) ---------------------------------------------------------------- {100,200,300} {1,2,3} {500,600}AVG
语法：
AVG(expr)功能：所有输入值的均值（算术平均）。
示例：
返回staffS表中MANAGER_ID的平均值。
CREATE TABLE staffS ( staff_ID NUMBER(6) not null, FIRST_NAME VARCHAR2(20), LAST_NAME VARCHAR2(25), EMAIL VARCHAR2(25), PHONE_NUMBER VARCHAR2(20), HIRE_DATE DATE, employment_ID VARCHAR2(10), SALARY NUMBER(8,2), COMMISSION_PCT NUMBER(2,2), MANAGER_ID NUMBER(6), section_ID NUMBER(4) );INSERT INTO staffs (staff_ID, FIRST_NAME, LAST_NAME, EMAIL, PHONE_NUMBER, HIRE_DATE, employment_ID, SALARY, COMMISSION_PCT, MANAGER_ID, section_ID) VALUES (198, 'Donald', 'OConnell', 'DOCONNEL', '650.507.9833', to_date('21-06-1999', 'dd-mm-yyyy'), 'SH_CLERK', 2600.00, null, 124, 50); INSERT INTO staffs (staff_ID, FIRST_NAME, LAST_NAME, EMAIL, PHONE_NUMBER, HIRE_DATE, employment_ID, SALARY, COMMISSION_PCT, MANAGER_ID, section_ID) VALUES (199, 'Douglas', 'Grant', 'DGRANT', '650.507.9844', to_date('13-01-2000', 'dd-mm-yyyy'), 'SH_CLERK', 2600.00, null, 124, 50); INSERT INTO staffs (staff_ID, FIRST_NAME, LAST_NAME, EMAIL, PHONE_NUMBER, HIRE_DATE, employment_ID, SALARY, COMMISSION_PCT, MANAGER_ID, section_ID) VALUES (200, 'Jennifer', 'Whalen', 'JWHALEN', '515.123.4444', to_date('17-09-1987', 'dd-mm-yyyy'), 'AD_ASST', 4400.00, null, 101, 10);SELECT AVG(MANAGER_ID) AS "AVG" FROM staffs; AVG ---------------------------------------- 116.333333333333333333333333333333333333 1 rows fetched.COUNT
语法：
COUNT(expr)功能：统计记录（列）数目。统计单列时，当列值不为空，将计数1；否则，计数为0。统计所有列，即count(*)时，即使列值为空，仍计数为1。
示例：
返回staffs表的记录数。
CREATE TABLE staffS ( staff_ID NUMBER(6) not null, FIRST_NAME VARCHAR2(20), LAST_NAME VARCHAR2(25), EMAIL VARCHAR2(25), PHONE_NUMBER VARCHAR2(20), HIRE_DATE DATE, employment_ID VARCHAR2(10), SALARY NUMBER(8,2), COMMISSION_PCT NUMBER(2,2), MANAGER_ID NUMBER(6), section_ID NUMBER(4) );INSERT INTO staffs (staff_ID, FIRST_NAME, LAST_NAME, EMAIL, PHONE_NUMBER, HIRE_DATE, employment_ID, SALARY, COMMISSION_PCT, MANAGER_ID, section_ID) VALUES (198, 'Donald', 'OConnell', 'DOCONNEL', '650.507.9833', to_date('21-06-1999', 'dd-mm-yyyy'), 'SH_CLERK', 2600.00, null, 124, 50); INSERT INTO staffs (staff_ID, FIRST_NAME, LAST_NAME, EMAIL, PHONE_NUMBER, HIRE_DATE, employment_ID, SALARY, COMMISSION_PCT, MANAGER_ID, section_ID) VALUES (199, 'Douglas', 'Grant', 'DGRANT', '650.507.9844', to_date('13-01-2000', 'dd-mm-yyyy'), 'SH_CLERK', 2600.00, null, 124, 50); INSERT INTO staffs (staff_ID, FIRST_NAME, LAST_NAME, EMAIL, PHONE_NUMBER, HIRE_DATE, employment_ID, SALARY, COMMISSION_PCT, MANAGER_ID, section_ID) VALUES (200, 'Jennifer', 'Whalen', 'JWHALEN', '515.123.4444', to_date('17-09-1987', 'dd-mm-yyyy'), 'AD_ASST', 4400.00, null, 101, 10);SELECT COUNT(staff_ID) AS "COUNT" FROM staffS; COUNT -------------------- 3 1 rows fetched.MAX
语法：
MAX(expr)功能：求最大值。可以用与数值型、日期型或字符型。当应用于字符型时，依照字母表顺序由后至前进行排序；当应用于日期型时，返回最晚日期。
示例：
返回staffS表中section_ID的最大值。
CREATE TABLE staffS ( staff_ID NUMBER(6) not null, FIRST_NAME VARCHAR2(20), LAST_NAME VARCHAR2(25), EMAIL VARCHAR2(25), PHONE_NUMBER VARCHAR2(20), HIRE_DATE DATE, employment_ID VARCHAR2(10), SALARY NUMBER(8,2), COMMISSION_PCT NUMBER(2,2), MANAGER_ID NUMBER(6), section_ID NUMBER(4) );INSERT INTO staffs (staff_ID, FIRST_NAME, LAST_NAME, EMAIL, PHONE_NUMBER, HIRE_DATE, employment_ID, SALARY, COMMISSION_PCT, MANAGER_ID, section_ID) VALUES (198, 'Donald', 'OConnell', 'DOCONNEL', '650.507.9833', to_date('21-06-1999', 'dd-mm-yyyy'), 'SH_CLERK', 2600.00, null, 124, 50); INSERT INTO staffs (staff_ID, FIRST_NAME, LAST_NAME, EMAIL, PHONE_NUMBER, HIRE_DATE, employment_ID, SALARY, COMMISSION_PCT, MANAGER_ID, section_ID) VALUES (199, 'Douglas', 'Grant', 'DGRANT', '650.507.9844', to_date('13-01-2000', 'dd-mm-yyyy'), 'SH_CLERK', 2600.00, null, 124, 50); INSERT INTO staffs (staff_ID, FIRST_NAME, LAST_NAME, EMAIL, PHONE_NUMBER, HIRE_DATE, employment_ID, SALARY, COMMISSION_PCT, MANAGER_ID, section_ID) VALUES (200, 'Jennifer', 'Whalen', 'JWHALEN', '515.123.4444', to_date('17-09-1987', 'dd-mm-yyyy'), 'AD_ASST', 4400.00, null, 101, 10);SELECT MAX(section_ID) AS "MAX" FROM staffs; MAX ---------------------------------------- 50 1 rows fetched.MEDIAN
语法：
MEDIAN(expr)功能：求中位数。中位数是数据排序后中间的数据，如果查询结果集为偶数个则中位数是中间两个数的平均值。
示例：
返回staffS表中staff_ID的中位数。
--删除表STAFFS。 DROP TABLE IF EXISTS STAFFS;--创建表STAFFS。 CREATE TABLE STAFFS ( staff_ID NUMBER(6) not null, FIRST_NAME VARCHAR2(20), LAST_NAME VARCHAR2(25), EMAIL VARCHAR2(25), PHONE_NUMBER VARCHAR2(20), HIRE_DATE DATE, employment_ID VARCHAR2(10), SALARY NUMBER(8,2), COMMISSION_PCT NUMBER(2,2), MANAGER_ID NUMBER(6), section_ID NUMBER(4) );--向表STAFFS插入记录。 INSERT INTO STAFFS (staff_ID, FIRST_NAME, LAST_NAME, EMAIL, PHONE_NUMBER, HIRE_DATE, employment_ID, SALARY, COMMISSION_PCT, MANAGER_ID, section_ID) VALUES (198, 'Donald', 'OConnell', 'DOCONNEL', '650.507.9833', to_date('21-06-1999', 'dd-mm-yyyy'), 'SH_CLERK', 2600.00, null, 124, 50); INSERT INTO STAFFS (staff_ID, FIRST_NAME, LAST_NAME, EMAIL, PHONE_NUMBER, HIRE_DATE, employment_ID, SALARY, COMMISSION_PCT, MANAGER_ID, section_ID) VALUES (199, 'Douglas', 'Grant', 'DGRANT', '650.507.9844', to_date('13-01-2000', 'dd-mm-yyyy'), 'SH_CLERK', 2600.00, null, 124, 50); INSERT INTO STAFFS (staff_ID, FIRST_NAME, LAST_NAME, EMAIL, PHONE_NUMBER, HIRE_DATE, employment_ID, SALARY, COMMISSION_PCT, MANAGER_ID, section_ID) VALUES (200, 'Jennifer', 'Whalen', 'JWHALEN', '515.123.4444', to_date('17-09-1987', 'dd-mm-yyyy'), 'AD_ASST', 4400.00, null, 101, 10);--返回数据列staff_ID的中位数。 SELECT MEDIAN(staff_ID) AS "MEDIAN" FROM STAFFS; MEDIAN ---------------------------------------- 199 1 rows fetched.MIN
语法：
MIN(expr)功能：求最小值。可以用与数值型、日期型或字符型。当应用于字符型时，依照字母表顺序由前至后进行排序；当应用于日期型时，返回最早日期。
示例：
返回staffS表中staff_ID的最小值。
CREATE TABLE staffS ( staff_ID NUMBER(6) not null, FIRST_NAME VARCHAR2(20), LAST_NAME VARCHAR2(25), EMAIL VARCHAR2(25), PHONE_NUMBER VARCHAR2(20), HIRE_DATE DATE, employment_ID VARCHAR2(10), SALARY NUMBER(8,2), COMMISSION_PCT NUMBER(2,2), MANAGER_ID NUMBER(6), section_ID NUMBER(4) );INSERT INTO staffs (staff_ID, FIRST_NAME, LAST_NAME, EMAIL, PHONE_NUMBER, HIRE_DATE, employment_ID, SALARY, COMMISSION_PCT, MANAGER_ID, section_ID) VALUES (198, 'Donald', 'OConnell', 'DOCONNEL', '650.507.9833', to_date('21-06-1999', 'dd-mm-yyyy'), 'SH_CLERK', 2600.00, null, 124, 50); INSERT INTO staffs (staff_ID, FIRST_NAME, LAST_NAME, EMAIL, PHONE_NUMBER, HIRE_DATE, employment_ID, SALARY, COMMISSION_PCT, MANAGER_ID, section_ID) VALUES (199, 'Douglas', 'Grant', 'DGRANT', '650.507.9844', to_date('13-01-2000', 'dd-mm-yyyy'), 'SH_CLERK', 2600.00, null, 124, 50); INSERT INTO staffs (staff_ID, FIRST_NAME, LAST_NAME, EMAIL, PHONE_NUMBER, HIRE_DATE, employment_ID, SALARY, COMMISSION_PCT, MANAGER_ID, section_ID) VALUES (200, 'Jennifer', 'Whalen', 'JWHALEN', '515.123.4444', to_date('17-09-1987', 'dd-mm-yyyy'), 'AD_ASST', 4400.00, null, 101, 10);SELECT MIN(staff_ID) AS "MIN" FROM staffs; MIN ---------------------------------------- 198 1 rows fetched.SUM
语法：
SUM(expr)功能：分组求和。
说明：expr必须是能够转为NUMBER的表达式。
示例：
返回staffS表中工资总和。
CREATE TABLE staffS ( staff_ID NUMBER(6) not null, FIRST_NAME VARCHAR2(20), LAST_NAME VARCHAR2(25), EMAIL VARCHAR2(25), PHONE_NUMBER VARCHAR2(20), HIRE_DATE DATE, employment_ID VARCHAR2(10), SALARY NUMBER(8,2), COMMISSION_PCT NUMBER(2,2), MANAGER_ID NUMBER(6), section_ID NUMBER(4) );INSERT INTO staffs (staff_ID, FIRST_NAME, LAST_NAME, EMAIL, PHONE_NUMBER, HIRE_DATE, employment_ID, SALARY, COMMISSION_PCT, MANAGER_ID, section_ID) VALUES (198, 'Donald', 'OConnell', 'DOCONNEL', '650.507.9833', to_date('21-06-1999', 'dd-mm-yyyy'), 'SH_CLERK', 2600.00, null, 124, 50); INSERT INTO staffs (staff_ID, FIRST_NAME, LAST_NAME, EMAIL, PHONE_NUMBER, HIRE_DATE, employment_ID, SALARY, COMMISSION_PCT, MANAGER_ID, section_ID) VALUES (199, 'Douglas', 'Grant', 'DGRANT', '650.507.9844', to_date('13-01-2000', 'dd-mm-yyyy'), 'SH_CLERK', 2600.00, null, 124, 50); INSERT INTO staffs (staff_ID, FIRST_NAME, LAST_NAME, EMAIL, PHONE_NUMBER, HIRE_DATE, employment_ID, SALARY, COMMISSION_PCT, MANAGER_ID, section_ID) VALUES (200, 'Jennifer', 'Whalen', 'JWHALEN', '515.123.4444', to_date('17-09-1987', 'dd-mm-yyyy'), 'AD_ASST', 4400.00, null, 101, 10);SELECT SUM(SALARY) AS "SUM" FROM staffs; SUM ---------------------------------------- 9600 1 rows fetched.STDDEV
语法：
STDDEV(expr)功能：分组求样本标准差，作为聚集函数或分析函数。
示例：
返回staffS表中工资的标准差。
CREATE TABLE staffS ( staff_ID NUMBER(6) not null, FIRST_NAME VARCHAR2(20), LAST_NAME VARCHAR2(25), EMAIL VARCHAR2(25), PHONE_NUMBER VARCHAR2(20), HIRE_DATE DATE, employment_ID VARCHAR2(10), SALARY NUMBER(8,2), COMMISSION_PCT NUMBER(2,2), MANAGER_ID NUMBER(6), section_ID NUMBER(4) );INSERT INTO staffs (staff_ID, FIRST_NAME, LAST_NAME, EMAIL, PHONE_NUMBER, HIRE_DATE, employment_ID, SALARY, COMMISSION_PCT, MANAGER_ID, section_ID) VALUES (198, 'Donald', 'OConnell', 'DOCONNEL', '650.507.9833', to_date('21-06-1999', 'dd-mm-yyyy'), 'SH_CLERK', 2600.00, null, 124, 50); INSERT INTO staffs (staff_ID, FIRST_NAME, LAST_NAME, EMAIL, PHONE_NUMBER, HIRE_DATE, employment_ID, SALARY, COMMISSION_PCT, MANAGER_ID, section_ID) VALUES (199, 'Douglas', 'Grant', 'DGRANT', '650.507.9844', to_date('13-01-2000', 'dd-mm-yyyy'), 'SH_CLERK', 2600.00, null, 124, 50); INSERT INTO staffs (staff_ID, FIRST_NAME, LAST_NAME, EMAIL, PHONE_NUMBER, HIRE_DATE, employment_ID, SALARY, COMMISSION_PCT, MANAGER_ID, section_ID) VALUES (200, 'Jennifer', 'Whalen', 'JWHALEN', '515.123.4444', to_date('17-09-1987', 'dd-mm-yyyy'), 'AD_ASST', 4400.00, null, 101, 10);SELECT STDDEV(SALARY) AS "STDDEV" FROM staffs; STDDEV ---------------------------------------- 1039.23048454132637611646780490352342017 1 rows fetched.STDDEV_SAMP
语法：
STDDEV_SAMP(expr)功能：分组求标准差，作为聚集函数或分析函数。
说明：当只有一行数据时，STDDEV返回0， 而STDDEV_SAMP返回null值。
示例：
返回staffS表中工资的样本标准差。
CREATE TABLE staffS ( staff_ID NUMBER(6) not null, FIRST_NAME VARCHAR2(20), LAST_NAME VARCHAR2(25), EMAIL VARCHAR2(25), PHONE_NUMBER VARCHAR2(20), HIRE_DATE DATE, employment_ID VARCHAR2(10), SALARY NUMBER(8,2), COMMISSION_PCT NUMBER(2,2), MANAGER_ID NUMBER(6), section_ID NUMBER(4) );INSERT INTO staffs (staff_ID, FIRST_NAME, LAST_NAME, EMAIL, PHONE_NUMBER, HIRE_DATE, employment_ID, SALARY, COMMISSION_PCT, MANAGER_ID, section_ID) VALUES (198, 'Donald', 'OConnell', 'DOCONNEL', '650.507.9833', to_date('21-06-1999', 'dd-mm-yyyy'), 'SH_CLERK', 2600.00, null, 124, 50); INSERT INTO staffs (staff_ID, FIRST_NAME, LAST_NAME, EMAIL, PHONE_NUMBER, HIRE_DATE, employment_ID, SALARY, COMMISSION_PCT, MANAGER_ID, section_ID) VALUES (199, 'Douglas', 'Grant', 'DGRANT', '650.507.9844', to_date('13-01-2000', 'dd-mm-yyyy'), 'SH_CLERK', 2600.00, null, 124, 50); INSERT INTO staffs (staff_ID, FIRST_NAME, LAST_NAME, EMAIL, PHONE_NUMBER, HIRE_DATE, employment_ID, SALARY, COMMISSION_PCT, MANAGER_ID, section_ID) VALUES (200, 'Jennifer', 'Whalen', 'JWHALEN', '515.123.4444', to_date('17-09-1987', 'dd-mm-yyyy'), 'AD_ASST', 4400.00, null, 101, 10); INSERT INTO staffs (staff_ID, FIRST_NAME, LAST_NAME, EMAIL, PHONE_NUMBER, HIRE_DATE, employment_ID, SALARY, COMMISSION_PCT, MANAGER_ID, section_ID) VALUES (198, 'Donald', 'OConnell', 'DOCONNEL', '650.507.9833', to_date('21-06-1999', 'dd-mm-yyyy'), 'SH_CLERK', 2600.00, null, 124, 50);SELECT STAFF_ID, FIRST_NAME, SALARY, STDDEV_SAMP(SALARY) OVER (PARTITION BY staff_ID) AS "samp" FROM staffs; STAFF_ID FIRST_NAME SALARY samp ---------------------------------------- -------------------- ---------------------------------------- ---------------------------------------- 198 Donald 2600 0 198 Donald 2600 0 199 Douglas 2600 200 Jennifer 4400STDDEV_POP
语法：
STDDEV_POP(expr)功能：分组求数据集的标准差，作为聚集函数或分析函数。
说明：STDDEV_POP是计算一组确定数值的标准差，而不是抽样中样本标准差，返回方差的算术平方根，计算公式和STDDEV稍有不同。
示例：
返回staffS表中工资的总体标准差和样本标准差。
CREATE TABLE staffS ( staff_ID NUMBER(6) not null, FIRST_NAME VARCHAR2(20), LAST_NAME VARCHAR2(25), EMAIL VARCHAR2(25), PHONE_NUMBER VARCHAR2(20), HIRE_DATE DATE, employment_ID VARCHAR2(10), SALARY NUMBER(8,2), COMMISSION_PCT NUMBER(2,2), MANAGER_ID NUMBER(6), section_ID NUMBER(4) );INSERT INTO staffs (staff_ID, FIRST_NAME, LAST_NAME, EMAIL, PHONE_NUMBER, HIRE_DATE, employment_ID, SALARY, COMMISSION_PCT, MANAGER_ID, section_ID) VALUES (198, 'Donald', 'OConnell', 'DOCONNEL', '650.507.9833', to_date('21-06-1999', 'dd-mm-yyyy'), 'SH_CLERK', 2600.00, null, 124, 50); INSERT INTO staffs (staff_ID, FIRST_NAME, LAST_NAME, EMAIL, PHONE_NUMBER, HIRE_DATE, employment_ID, SALARY, COMMISSION_PCT, MANAGER_ID, section_ID) VALUES (199, 'Douglas', 'Grant', 'DGRANT', '650.507.9844', to_date('13-01-2000', 'dd-mm-yyyy'), 'SH_CLERK', 2600.00, null, 124, 50); INSERT INTO staffs (staff_ID, FIRST_NAME, LAST_NAME, EMAIL, PHONE_NUMBER, HIRE_DATE, employment_ID, SALARY, COMMISSION_PCT, MANAGER_ID, section_ID) VALUES (200, 'Jennifer', 'Whalen', 'JWHALEN', '515.123.4444', to_date('17-09-1987', 'dd-mm-yyyy'), 'AD_ASST', 4400.00, null, 101, 10); INSERT INTO staffs (staff_ID, FIRST_NAME, LAST_NAME, EMAIL, PHONE_NUMBER, HIRE_DATE, employment_ID, SALARY, COMMISSION_PCT, MANAGER_ID, section_ID) VALUES (198, 'Donald', 'OConnell', 'DOCONNEL', '650.507.9833', to_date('21-06-1999', 'dd-mm-yyyy'), 'SH_CLERK', 2600.00, null, 124, 50);SELECT STDDEV_POP(SALARY) "Pop", STDDEV_SAMP(SALARY) "Samp" FROM staffs; Pop Samp ---------------------------------------- ---------------------------------------- 779.422863405994782087350853677642565124 900 1 rows fetched.GROUP_CONCAT
语法：
GROUP_CONCAT([DISTINCT] expr1 [, expr2...] [ORDER BY {unsigned_integer | col_name | expr} [ASC | DESC] [, col_name...]] [SEPARATOR str_val])功能：分组进行字符串连接，并在连接时用指定的分隔符隔开。
说明：
- 如果用户指定了两个及以上表达式，则该函数在分组进行字符串连接之前会先将指定的多个表达式进行字符串连接，但此时的连接并没有任何分隔符。
- 默认的分隔符为逗号","。
- 函数最多支持64个参数，GROUP_CONCAT函数的分隔符占用一个参数，实际最大支持63个参数。
示例：
按staff_ID分组，连接SALARY的值。
CREATE TABLE staffS ( staff_ID NUMBER(6) not null, FIRST_NAME VARCHAR2(20), LAST_NAME VARCHAR2(25), EMAIL VARCHAR2(25), PHONE_NUMBER VARCHAR2(20), HIRE_DATE DATE, employment_ID VARCHAR2(10), SALARY NUMBER(8,2), COMMISSION_PCT NUMBER(2,2), MANAGER_ID NUMBER(6), section_ID NUMBER(4) );INSERT INTO staffs (staff_ID, FIRST_NAME, LAST_NAME, EMAIL, PHONE_NUMBER, HIRE_DATE, employment_ID, SALARY, COMMISSION_PCT, MANAGER_ID, section_ID) VALUES (198, 'Donald', 'OConnell', 'DOCONNEL', '650.507.9833', to_date('21-06-1999', 'dd-mm-yyyy'), 'SH_CLERK', 2600.00, null, 124, 50); INSERT INTO staffs (staff_ID, FIRST_NAME, LAST_NAME, EMAIL, PHONE_NUMBER, HIRE_DATE, employment_ID, SALARY, COMMISSION_PCT, MANAGER_ID, section_ID) VALUES (199, 'Douglas', 'Grant', 'DGRANT', '650.507.9844', to_date('13-01-2000', 'dd-mm-yyyy'), 'SH_CLERK', 2600.00, null, 124, 50); INSERT INTO staffs (staff_ID, FIRST_NAME, LAST_NAME, EMAIL, PHONE_NUMBER, HIRE_DATE, employment_ID, SALARY, COMMISSION_PCT, MANAGER_ID, section_ID) VALUES (200, 'Jennifer', 'Whalen', 'JWHALEN', '515.123.4444', to_date('17-09-1987', 'dd-mm-yyyy'), 'AD_ASST', 4400.00, null, 101, 10); INSERT INTO staffs (staff_ID, FIRST_NAME, LAST_NAME, EMAIL, PHONE_NUMBER, HIRE_DATE, employment_ID, SALARY, COMMISSION_PCT, MANAGER_ID, section_ID) VALUES (198, 'Donald', 'OConnell', 'DOCONNEL', '650.507.9833', to_date('21-06-1999', 'dd-mm-yyyy'), 'SH_CLERK', 2600.00, null, 124, 50);SELECT staff_ID,GROUP_CONCAT(SALARY) FROM staffs GROUP BY staff_ID; STAFF_ID GROUP_CONCAT(SALARY) ---------------------------------------- ---------------------------------------------------------------- 200 4400 198 2600,2600 199 2600 3 rows fetched.「喜欢这篇文章，您的关注和赞赏是给作者最好的鼓励」关注作者【版权声明】本文为墨天轮用户原创内容，转载时必须标注文章的来源（墨天轮），文章链接，文章作者等基本信息，否则作者和墨天轮有权追究责任。如果您发现墨天轮中有涉嫌抄袭或者侵权的内容，欢迎发送邮件至：contact@modb.pro进行举报，并提供相关证据，一经查实，墨天轮将立刻删除相关内容。评论
