更新时间:2024-03-07 GMT+08:00
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函数

支持的函数

表1 操作符函数

函数表达式

示例

IN

SELECT * FROM Products WHERE vendor_id IN ( 'V000001', 'V000010' ) ORDER BY product_price;

NOT IN

SELECT product_id, product_name FROM Products WHERE NOT vendor_id IN ('V000001', 'V000002') ORDER BY product_id;

BETWEEN

SELECT id, product_id, product_name, product_price FROM Products WHERE id BETWEEN 000005 AND 000034 ORDER BY id;

NOT…BETWEEN

SELECT product_id, product_name FROM Products WHERE NOT vendor_id BETWEEN 'V000002' and 'V000005' ORDER BY product_id;

IS NULL

SELECT product_name FROM Products WHERE product_price IS NULL;

IS NOT NULL

SELECT id, product_name FROM Products WHERE product_price IS NOT NULL ORDER BY id;

AND

SELECT * FROM Products WHERE vendor_id = 'V000001' AND product_price <= 4000 ORDER BY product_price;

OR

SELECT * FROM Products WHERE vendor_id = 'V000001' OR vendor_id = 'V000009';

NOT

SELECT product_id, product_name FROM Products WHERE NOT vendor_id = 'V000002';

LIKE

SELECT * FROM Products WHERE product_name LIKE 'NAME%' ORDER BY product_name;

NOT LIKE

SELECT * FROM Products WHERE product_name NOT LIKE 'NAME%' ORDER BY product_name;

CONCAT

SELECT product_id, product_name, Concat( product_id , '(', product_name ,')' ) AS product_test FROM Products ORDER BY product_id;

+

SELECT 3 * 2+5-100/50;

-

SELECT 3 * 2+5-100/50;

*

SELECT order_num, product_id, quantity, item_price, quantity*item_price AS expanded_price FROM OrderItems WHERE order_num BETWEEN 000009 AND 000028 ORDER BY order_num;

/

SELECT 3 * 2+5-100/50;

UPPER

SELECT id, product_id, UPPER(product_name) FROM Products WHERE id > 10 ORDER BY product_id;

LOWER

SELECT id, product_id, LOWER(product_name) FROM Products WHERE id <= 10 ORDER BY product_id;

SOUNDEX

SELECT * FROM Vendors WHERE SOUNDEX(vendor_name) = SOUNDEX('test') ORDER BY vendor_name;

IFNULL

SELECT IFNULL(product_id, 0) FROM Products;

表2 时间日期函数

函数表达式

示例

支持范围

DAY()

SELECT * FROM TAB_DATE WHERE DAY(date)=21;

SELECT * FROM TAB_DATE WHERE date='2018-12-21';

INSERT INTO TAB_DATE(id,date) VALUES(1,'2018-05-22');

-

MONTH()

SELECT * FROM TAB_DATE WHERE MONTH(date)=12;

SELECT * FROM TAB_DATE WHERE date='2018-12-21';

INSERT INTO TAB_DATE(id,date) VALUES(1,'2018-05-22');

-

YEAR()

SELECT * FROM TAB_DATE WHERE YEAR(date)=2018;

SELECT * FROM TAB_DATE WHERE date='2018-12-21';

INSERT INTO TAB_DATE(id,date) VALUES(1,'2018-05-22');

-

TIME()

SELECT * FROM TAB_DATE WHERE TIME(date)='01:02:03';

SELECT * FROM TAB_DATE WHERE date='2021-01-01 01:02:03';

INSERT INTO TAB_DATE(id,date) VALUES(1,'2021-01-01 01:02:03');

参数需为合法的时间、日期时间表达式或字符串。

TIME_TO_SEC()

SELECT * FROM TAB_DATE WHERE TIME_TO_SEC(date)=3603;

SELECT * FROM TAB_DATE WHERE date='2021-01-01 01:00:03';

INSERT INTO TAB_DATE(id,date) VALUES(1,'2021-01-01 01:00:03');

参数需为合法的时间、日期时间表达式或字符串。

SEC_TO_TIME()

SELECT * FROM TAB_DATE WHERE SEC_TO_TIME(date)='00:01:00';

SELECT * FROM TAB_DATE WHERE date=60;

INSERT INTO TAB_DATE(id,date) VALUES(1,60);

参数需为数值或可转化为数值的字符串。

SECOND()

SELECT * FROM TAB_DATE WHERE SECOND(date)=3;

SELECT * FROM TAB_DATE WHERE date='2021-01-01 01:02:03';

INSERT INTO TAB_DATE(id,date) VALUES(1,'2021-01-01 01:02:03');

参数需为合法的时间、日期时间表达式或字符串。

MINUTE()

SELECT * FROM TAB_DATE WHERE MINUTE(date)=2;

SELECT * FROM TAB_DATE WHERE date='2021-01-01 01:02:03';

INSERT INTO TAB_DATE(id,date) VALUES(1,'2021-01-01 01:02:03');

参数需为合法的时间、日期时间表达式或字符串。

HOUR()

SELECT * FROM TAB_DATE WHERE HOUR(date)=1;

SELECT * FROM TAB_DATE WHERE date='2021-01-01 01:02:03';

INSERT INTO TAB_DATE(id,date) VALUES(1,'2021-01-01 01:02:03');

参数需为合法的时间、日期时间表达式或字符串。

DAYNAME()

SELECT * FROM TAB_DATE WHERE DAYNAME(date)='Friday';

SELECT * FROM TAB_DATE WHERE date='2021-01-01 01:02:03';

INSERT INTO TAB_DATE(id,date) VALUES(1,'2021-01-01 01:02:03');

参数需为合法的日期、日期时间表达式或字符串。

MONTHNAME()

SELECT * FROM TAB_DATE WHERE MONTHNAME(date)='January';

SELECT * FROM TAB_DATE WHERE date='2021-01-01 01:02:03';

INSERT INTO TAB_DATE(id,date) VALUES(1,'2021-01-01 01:02:03');

参数需为合法的日期、日期时间表达式或字符串。

LAST_DAY()

SELECT * FROM TAB_DATE WHERE LAST_DAY(date)='2021-01-31';

SELECT * FROM TAB_DATE WHERE date='2021-01-01 01:02:03';

INSERT INTO TAB_DATE(id,date) VALUES(1,'2021-01-01 01:02:03');

参数需为合法的日期、日期时间表达式或字符串。

DAYOFWEEK()

SELECT * FROM TAB_DATE WHERE DAYOFWEEK(date)=6;

SELECT * FROM TAB_DATE WHERE date='2021-01-01 01:02:03';

INSERT INTO TAB_DATE(id,date) VALUES(1,'2021-01-01 01:02:03');

参数需为合法的日期、日期时间表达式或字符串。

DAYOFMONTH()

SELECT * FROM TAB_DATE WHERE DAYOFWEEK(date)=6;

SELECT * FROM TAB_DATE WHERE date='2021-01-01 01:02:03';

INSERT INTO TAB_DATE(id,date) VALUES(1,'2021-01-01 01:02:03');

参数需为合法的日期、日期时间表达式或字符串。

DAYOFYEAR()

SELECT * FROM TAB_DATE WHERE DAYOFYEAR(date)=365;

SELECT * FROM TAB_DATE WHERE date='2021-12-31 01:02:03';

INSERT INTO TAB_DATE(id,date) VALUES(1,'2021-12-31 01:02:03');

参数需为合法的日期、日期时间表达式或字符串。

WEEKOFYEAR()

SELECT * FROM TAB_DATE WHERE WEEKOFYEAR(date)=53;

SELECT * FROM TAB_DATE WHERE date='2021-12-31 01:02:03';

INSERT INTO TAB_DATE(id,date) VALUES(1,'2021-12-31 01:02:03');

参数需为合法的日期、日期时间表达式或字符串。

DATE_ADD(

date, INTERVAL expr unit

)

SELECT * FROM TAB_DATE WHERE DATE_ADD(date,INTERVAL 1 YEAR)='2022-01-01 01:02:03';

SELECT * FROM TAB_DATE WHERE date='2021-01-01 01:02:03';

INSERT INTO TAB_DATE(id,date) VALUES(1,'2021-01-01 01:02:03');

  • date参数需为合法的时间、日期、日期时间表达式或字符串。
  • expr为从date开始加减运算的间隔值,要求为整数或可转化为整数的字符串。
  • unit为单位,暂时可选SECOND, MINUTE, HOUR, DAY, WEEK, MONTH, QUARTER, YEAR。
  • 当date为日期类型时,"1000-01-01"是下边界。在运算时如果存在越界行为,运算可能出错。
  • date参数最高支持毫秒精度。

DATE_SUB(date, INTERVAL expr unit)

SELECT * FROM TAB_DATE WHERE DATE_SUB(date,INTERVAL -1 DAY)='2021-01-02 01:02:03';

SELECT * FROM TAB_DATE WHERE date='2021-01-02 01:02:03';

INSERT INTO TAB_DATE(id,date) VALUES(1,'2021-01-02 01:02:03');

  • date参数需为合法的时间、日期、日期时间表达式或字符串。
  • expr为从date开始加减运算的间隔值,要求为整数或可转化为整数的字符串。
  • unit为单位,暂时可选SECOND, MINUTE, HOUR, DAY, WEEK, MONTH, QUARTER, YEAR。
  • 当date为日期类型时,"1000-01-01"是下边界。在运算时如果存在越界行为,运算可能出错。
  • date参数最高支持毫秒精度。
表3 数学函数

函数表达式

示例

支持范围

SQRT()

SELECT id, product_price, SQRT(product_price) AS price_sqrt FROM Products WHERE product_price < 4000 ORDER BY product_price;

-

AVG()

SELECT AVG(product_price) AS avg_product FROM Products;

-

COUNT()

SELECT COUNT(*) AS num_product FROM Products;

-

MAX()

SELECT id, product_id, product_name, MAX(product_price) AS max_price FROM Products ORDER BY id;

-

MIN()

SELECT id, product_id, product_name, MIN(product_price) AS min_price FROM Products ORDER BY id;

-

SUM()

SELECT SUM(product_price) AS sum_product FROM Products;

-

ROUND()

SELECT ROUND(product_price) AS round_product FROM Products;

参数需为数值或可转化为数值的字符串。

SIN()

SELECT SIN(x) AS sin_x FROM math_tbl;

参数需为数值或可转化为数值的字符串。

COS()

SELECT COS(x) AS cos_x FROM math_tbl;

参数需为数值或可转化为数值的字符串。

TAN()

SELECT TAN(x) AS tan_x FROM math_tbl;

参数需为数值或可转化为数值的字符串。

COT()

SELECT COT(x) AS cot_x FROM math_tbl;

参数需为数值或可转化为数值的字符串。

FLOOR()

SELECT FLOOR(product_price) AS floor_product FROM Products;

参数需为数值或可转化为数值的字符串。

CEILING()

SELECT CEILING(product_price) AS ceiling_product FROM Products;

参数需为数值或可转化为数值的字符串。

ABS()

SELECT ABS(x) AS abs_x FROM math_tbl;

参数的范围为-9223372036854775807到9223372036854775807,超过此范围会报错。

LOG()

SELECT LOG(x) AS log_x FROM math_tbl;

参数需为大于0的数值或可转化为相应数值的字符串。

LN()

SELECT LN(x) AS ln_x FROM math_tbl;

参数需为大于0的数值或可转化为相应数值的字符串。

EXP()

SELECT EXP(x) AS exp_x FROM math_tbl;

参数的范围为-∞到709,超过此范围会报错。

表4 字符串函数

函数表达式

示例

支持范围

TRIM()

SELECT TRIM(' hello, world ') AS trim_character FROM Character;

参数需为字符串相关类型。

使用前,请先查看该函数是否在支持范围,建议使用支持范围内的函数。如果在范围外使用,返回结果与MySQL中的返回结果可能不一致。

不支持的函数

表5 函数的限制

函数

限制条件

ROW_COUNT()

DDM 暂不支持ROW_COUNT()函数。

COMPRESS()

DDM 暂不支持COMPRESS()函数。如果无法确认函数是否能下推到RDS,请不要使用该函数。

SHA()

DDM 暂不支持SHA()函数。如果无法确认函数是否能下推到RDS,请不要使用该函数。

SHA1()

DDM 暂不支持SHA1()函数。如果无法确认函数是否能下推到RDS,请不要使用该函数。

MD5()

DDM 暂不支持MD5()函数。如果无法确认函数是否能下推到RDS,请不要使用该函数。

AES_ENCRYPT()

DDM 暂不支持AES_ENCRYPT()函数。如果无法确认函数是否能下推到RDS,请不要使用该函数。

AES_DECRYPT()

DDM 暂不支持AES_DECRYPT()函数。如果无法确认函数是否能下推到RDS,请不要使用该函数。

YEARWEEK()

DDM 暂不支持YEARWEEK()函数。如果无法确认函数是否能下推到RDS,请不要使用该函数。

TIME_FORMAT()

DDM暂不支持TIME_FORMAT()函数。如果无法确认函数是否能下推到RDS,请不要使用该函数,建议使用DATE_FORMAT()函数。

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