Mariusz Sakowski questions

Mariusz Sakowski answers

• how scala treat companion object?
• MySQL REPLACE behaves differently than UPDATE if the PRIMARY KEY is referenced by a FOREIGN KEY
• MySQL & nested set: slow JOIN (not using index)
• Count distinct multiple columns in redshift
• PDOstatement (MySQL): inserting value 0 into a bit(1) field results in 1 written in table
• PHP - Ampersand before the variable in foreach loop [duplicate]
• Comparing int to string causes weird results in php? [duplicate]
• Why cannot disable PDO::ATTR_EMULATE_PREPARES?