Search results
29 lis 2019 · If the column might be a blank string or null, I'd rather fix this before doing the select each time, like this: UPDATE MyTable SET MyColumn=NULL WHERE MyColumn=''; SELECT * FROM MyTable WHERE MyColumn IS NULL This keeps the data tidy, as long as you don't specifically need to differentiate between NULL and empty for some reason.
18 mar 2014 · SELECT t.phone, t.phone2 FROM jewishyellow.users t WHERE t.phone LIKE '813%' AND t.phone2 > ''. Notice the > '' part, which will check if the value is not null, and if the value isn't just whitespace or blank. Basically, if the field has something in it other than whitespace or NULL, it is true.
15 wrz 2019 · You need to do it in two steps, first generate the sql like (assuming your table is named T in schema S: select concat (' SELECT * FROM t WHERE ''a'' in (' , GROUP_CONCAT (COLUMN_NAME) , ')') from INFORMATION_SCHEMA.columns where table_schema = 's' and table_name = 't' and DATA_TYPE IN ('char','varchar');
6 cze 2024 · We can use the function NULLIF to compare and check if the column contains null or empty values: SELECT id, name FROM Department WHERE NULLIF(TRIM(code), '') IS NULL; The NULLIF function evaluates its two arguments, returning NULL if they are equal.
Functions for Use in SELECT and WHERE Clauses. A select_expression or where_definition in a SQL statement can consist of any expression using the functions described next. An expression that contains NULL always produces a NULL value unless otherwise indicated in the documentation for the operators and functions involved in the expression.
Introduction to MySQL WHERE clause. The WHERE clause allows you to specify a search condition for the rows returned by a query. The following shows the syntax of the WHERE clause: SELECT select_list FROM table_name WHERE search_condition; Code language: SQL (Structured Query Language) (sql)
12 maj 2024 · We can use the LIKE operator to perform a wildcard search on the columns: SELECT * FROM Product WHERE description LIKE '%Milk%' OR description LIKE '%Dark%'; The LIKE operator combined with % on both sides of the search terms allows for flexible searching.
