Players and Championships tables on the condition that player_id matches any of the winner columns in Championships.SUM function with a conditional statement to count the number of grand slam titles for each player. This is done by adding 1 for each match of player_id with the winner columns and 0 otherwise.player_id and player_name to get the total count of grand slam titles for each player.player_id, player_name, and the sum as grand_slams_count to form the final output.
erDiagram
Players {
int player_id PK
varchar player_name
}
Championships {
int year PK
int Wimbledon
int Fr_open
int US_open
int Au_open
}