在MySQL数据库中搜索多个表

Question

I have several different tables in my database(mySQL).

Here are the relevant coumns for the tables

table_tournaments

1. tournamentId
2. tournamnetName
3. tournamentStatus

table_tournament_results

1. tournamentId
2. playerId
3. playerName
4. playerRank
5. tournamnetParticipants

table_players

1. playerId
2. playerName

The tournaments table contains the information about the tournament, the tournament results table shows the results from that table

I want to search the tournaments table by name and then with the returned results get the information from the tournament results table.

    SELECT * FROM `tournaments` `WHERE` `tournamentName` LIKE "%Query%"

I'm not sure how to go about this, maybe I need to do something via PHP , any and all help is appreciated.

Answer 1

You can get the results you want with a join operation.

This is an example of an outer join , returning all rows from t that have the string 'foo' appearing as part of tournament_name , along with any matching rows from r .

A relationship between rows in the two tables is established by storing a common value in the tournamentId column of the two tables. The predicate in the ON clause specifies the condition that determines if a row "matches".

 SELECT t.tournamentId
      , t.tournamentName
      , t.tournamentStatus
      , r.playerId
      , r.playerName
      , r.playerRank
   FROM table_tournaments t
   LEFT
   JOIN table_tournament_results r
     ON r.tournamentId = t.tournamentId
  WHERE t.tournament_name LIKE '%foo%'
  ORDER
     BY t.tournamentId
      , r.playerId

The t and r that appear after the table names are table aliases , we can qualify references to the columns in each table by prefacing the column name with the table alias and a dot. This makes the column reference unambiguous. (In the case of tournamentId , MySQL doesn't know if you are referring to the column in t or r , so we qualify it to make it explicit. We follow this same pattern for all column references. Then, someone reading the statement doesn't need to wonder which table contains the column playerId .

Answer 2

Your Query may be like this

SELECT a.*, b.tournamnetName FROM table_tournament_results a 
left join table_tournaments on a.tournamentId=b.tournamentId
WHERE b.tournamnetName LIKE "%Query%"