distributed-database-middleware/umn/source/sql_syntax/functions.rst

original_name

ddm_03_0063.html

Functions

Supported Functions

Table 1 Operator functions

Expression	Example
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; Note For DDM instances created before March 20, sharded tables do not support the calling of functions nested in the IFNULL and aggregation functions. For example, if you execute function select IFNULL(sum(yan),0) from shenhai, the result differs from the expected result. For DDM instances created after March 20, sharded tables support only the calling of functions nested in the IFNULL and aggregation functions.

Table 2 Time and date functions

Expression	Example	Application Scope
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')	-

Table 3 Mathematical functions

Expression	Example	Application Scope
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	-

Unsupported Functions

Table 4 Function restrictions

Item	Restriction
ROW_COUNT()	Function ROW_COUNT() is not supported.