I am having 3 tables (c19 , c19b2, g26) in a database
I want to write a SQL Query to search and display all fields of the matched record.
I am using following query:
$query = "SELECT * FROM c19,c19b2,g26 WHERE armyno LIKE '%$searchTerm%'";
But it only works for table c19,
Data from the other 2 tables is not fetched.Each table has a field armyno
Please help me with this
Thank you.
Alright, you are not looking for a JOIN, but a UNION.
SELECT * FROM c19 WHERE armyno LIKE '%$searchTerm%'
UNION
SELECT * FROM c19b2 WHERE armyno LIKE '%$searchTerm%'
UNION
SELECT * FROM g26 WHERE armyno LIKE '%$searchTerm%'
That will let you query all three tables at the same time.
Which DB are you using? This would have worked in SQL Server. However, notice you are doing a cross join of every record to every record... usually you only want to match some records by restriction of a matching key, for example:
select
*
from a
left join b on b.somekey = a.somekey
left join c on c.someotherkey = b.someotherkey
In SQL server you can just say *, but I'm taking it that in your DB engine that didn't work, so try specifying which table. This may in some environments require aliasing as well:
select
a.*,
b.*,
c.*
from tableA as a
left join tableB as b on b.somekey = a.somekey
left join tableC as c on c.someotherkey = b.someotherkey
Generally, you should see the columns from the first table, followed by the columns from the second table, followed by columns from the third table for a given row. If you wanted to get all columns from all tables, but separately, then that would be 3 separate selects.
Lastly, if all 3 tables have "armyno" then I'd expect it to throw an ambiguous field error. In such case you'd want to specify which table's "armyno" field to filter on.
Related
I have two tables and I want to join them to get the desired output.
Say the 1st table (seat1) is
and the 2nd table (collegestudents) is
The desired output is
I have tried the below code. But it fails to give the desired result.
$rde2=mysqli_query($con, "select * from seat1 s
left JOIN collegestudents c ON c.Roll = s.Roll
");
Any help please.
You want a left join. Your query looks fine, but you would need not to use select *, and instead explictly list the columns that you want to select, using table prefixes. Otherwise, since you have a Roll column in both tables, a name clashes will happen, that your application apparently does not handle well.
select
s.Roll,
c.Name,
s.Subject
from seat1 s
left join collegestudents c on c.Roll = s.Roll
I need to change the column name while joining the MySQL query. I am explaining my code below.
select * from grc_action left join grc_users on grc_action.action_owner=grc_users.user_id
I am giving my table below.
grc_action:
id name action_owner
grc_users:
user_id name
The above is my table structure and as both has same column name i.e-name here I need to change the grc_users table column i.e-name while fetching the record. Please help me to solve this problem.
You can use AS
SELECT table1.name AS exampleName, table2.name AS otherName FROM sometable
You can also use this on tables:
SELECT vltn.id, vltn.name FROM veryLongTableName AS vltn
You dont need to type the AS, you can just do SELECT table1.name exampleName to shorten it, but it increases readbility and maintanability to write it, so I recommend doing it with AS.
You may assign different aliases to the name columns from the two different tables.
select
ga.id,
ga.name as action_name,
ga.action_owner,
gu.user_id,
gu.name as user_name
from grc_action ga
left join grc_users gu
on ga.action_owner = gu.user_id;
Note that I also used table aliases which make the query easier to read. In general, doing SELECT * is undesirable, and it is usually better to explicitly list the columns you want.
select *
from grc_action
left join grc_users on grc_action.action_owner=grc_users.user_id
changed query use this query
select *,grc_users.name as grcuser_name,grc_action.name as grcaction_name
from grc_action
left join grc_users on grc_action.action_owner=grc_users.user_id
Here geting two name like this
grcuser_name ,
grcaction_name
I'm using the following query to pull data from 3 tables. 2 are in the same database and 1 in a different database. Basically I have recipes in one table, and I'm using the recipieToCountry table to connect to the countries table so I know what country a recipe belongs to.
$contentQuery = $page->dbf->query("
SELECT *
FROM recipes, recipeToCountry, content.countries
WHERE recipes.id = recipeToCountry.recipeId
AND recipeToCountry.countryId = content.countries.id
AND content.countries.origId = '$country'
");
The problem I'm running into is when I call $content->title it returns the title from countries when I want the title from recipies. My understanding is SELECT * is the issue, so I tried to change the query to this:
SELECT title, description, approved, active, id, recipeId, countryId
FROM recipes, recipeToCountry
WHERE recipes.id = recipeToCountry.recipeId
UNION
SELECT id, origId, null, null, null, null, null
FROM content.countries
WHERE content.countries.origId = 1
AND recipeToCountry.countryId = content.countries.id
Unfortunately this query has an error, and I'm unsure how to fix it. When I removed the last AND the UNION doesn't seem to work as well. Any ideas on what changes I could make to get the correct columns?
Simple JOINs should work well:
select r.*, c.*
from recipes r
join repiceToCountry rc on r.id = rc.recipeId
join content.countries c on c.id = rc.countryId
where c.origId = '$country'
You must make sure you have SELECT privileges on the other database.
Also, you can replace r.*, c.* by the specific columns you want to show.
I developed a habit a long time ago of always putting the table alias/name before every field in the query. This way you can modify the query later on without worrying about fields names that conflict when you add tables to the query. I also prefer joins to multiple FROM tables. (It's easier to see the logic)
I would change your first query to this:
SELECT r.*, c.country /* any other fields in country besides title */
FROM recipes as r
LEFT JOIN recipeToCountry as rtc ON rtc.recipeId = r.id
LEFT JOIN content.countries as c ON c.id = rtc.countryId
WHERE c.origId = '$country'
You can leave the word "as" out to make it look a little cleaner, but I leave it in there to show what's happening a little better.
So, I am trying to select some data from 4 tables using a query I have attempted to throw together.
SELECT *
FROM cards
LEFT JOIN cards_viewers ON cards.card_id = cards_viewers.card_id
(SELECT *
FROM folders
WHERE folder_id = cards.card_folderID)
(SELECT user_firstName,
user_lastName,
user_avatar
FROM user_data
WHERE user_id = cards_viewers.user_id)
WHERE cards_viewers.user_id = '.$u_id.'
ORDER BY cards.card_lastUpdated DESC
Basically, the query selects data from the four tables depending on the user_id in table user_data. I have attempted to initially fetch all data from the tables cards, and cards_viewers, and have went on to use this data to select values from the other tables (user_data and folders).
The query is wrong, I know that. I have learnt the majority of basic MySQL, but I am still struggling with more complex queries like the one I am trying to write now. What query can I use to select the data I want?
Links to any documentation to parts of queries would prove very useful in helping me learn how to create queries in future, rather than just relying on StackOverflow.
Many thanks.
You don't need "MULTI-WHERE" but multiple joins, you just need to keep doing joins until you get the tables you need.
Here's an example:
SELECT *
FROM cards LEFT JOIN cards_viewers
ON cards.card_id = cards_viewers.card_id
LEFT JOIN folders
ON folders.folder_id = cards.card_folderID
LEFT JOIN user_data
ON user_id = cards_viewers.user_id
WHERE cards_viewers.user_id = '.$u_id.'
ORDER BY cards.card_lastUpdated DESC
To custom the fields you want to get just change * for the name of the field being careful about ambiguous column naming.
For further information check MySql Joins. Hope this helped you :)
I have two table in the same database: hlstats_Events_Connects and hlstats_PlayerUniqueIds.
In the hlstats_Events_Connects I have a value I wish to get, however the ID it's related to I need to get from the data in another table, using the "uniqueId" that I have. Example:
**hlstats_Events_Connects**
playerId eventTime
----------------------
8 2013-04-05 05:44:14
**hlstats_PlayerUniqueIds**
playerId uniqueId
---------------------
8 0:0:84901
So I have the "uniqueId" as a variable, and I want to say, get the playerId of the persons uniqueId, then get the eventTime from what the playerId is. Currently I have something along the lines of the below, but can't figure out the Where clause.
SELECT c.eventTime, c.playerId, u.uniqueId, u.playerId
FROM c.hlstats_Events_Connects, u.hlstats_PlayerUniqueIds
WHERE ...?
Cheers
Looks like you are just missing the JOIN. You will join the tables on the playerId column:
SELECT c.eventTime, c.playerId, u.uniqueId, u.playerId
FROM c.hlstats_Events_Connects c
INNER JOIN u.hlstats_PlayerUniqueIds u
ON c.playerId = u.playerId
Note, I updated the query to use ANSI JOIN syntax, in this case an INNER JOIN. This is standard SQL syntax, instead of commas between the tables and the join in the WHERE
Use JOIN like this
SELECT c.eventTime, c.playerId, u.uniqueId, u.playerId
FROM c.hlstats_Events_Connects, u.hlstats_PlayerUniqueIds
WHERE c.playerId = u.playerId
You don't need to add prefixes to table names, instead those should be specified after table name, and also you can just join on playerId column (if those are large tables, I'd suggest adding an index to those columns.)
SELECT
c.eventTime, c.playerId, u.uniqueId, u.playerId
FROM
hlstats_Events_Connects c,
hlstats_PlayerUniqueIds u
WHERE
u.uniqueId = "0:0:84901" and
u.playerId = c.playerId