Wildcard can't find the string in table sql query-CodePudding

I'm studying SQL now.

SELECT * 
FROM dates 
WHERE user_id = '1891128461' 
  AND date1 = 'shop*'

This query can't find the data, while the following did find it:

SELECT * 
FROM dates 
WHERE user_id = '1891128461' 
  AND date1 = 'shopmeal'

What is in my wildcard query is wrong?

I had followed this explanation:

* represents zero or more characters; bl* finds bl, black, blue, and blob

and % returns the same output (see output of variable values)

   command -->['/s', 'shop%']
 'date1, date2, date3' --> shop%
['date1,', 'date2,', 'date3']--> ['shop%']
items for shop% does  not exist

While if full word, it find (see output of variable values)

 /s shophardware
command -->['/s', 'shophardware']
 'date1, date2, date3' --> shophardware
['date1,', 'date2,', 'date3']--> ['shophardware']
items in a hardware  category
 - wires 2mm  sink  fan tubes 100mm

CodePudding user response：

The way you say AND date1='shop*' in SQL is

AND date1 LIKE 'shop%'

% matches any string of zero or more characters, and _ matches just one character. To get this kind of matching, you must say LIKE rather than =.

SQL's wildcard scheme evolved separately from UNIX's glob and regular expression scheme.