How echo data from 3 different databases after selection? - php

Have 3 tables called "table1" "table2" and "table3". Only the column id is same in these tables. All other columns are different.
Will select like:
"select * from table1, table2, table3 where WHERE (date >= now())";
I am facing problem while echoing the data. The table1 have one column called "org", table2 have "name", table3 have "pgm". I want something like:
echo "$data['org']" OR $data['name'] OR $data['pgm']"
Is this possible?

So, assuming what you said is true:
Only the column id is the same in these tables
Then you can join the tables that share this column value and retrieve the values back in a query:
SELECT t1.org,
t2.name,
t3.pgm
FROM table1 t1
INNER JOIN table2 t2
ON t2.id = t1.id
INNER JOIN table3 t3
ON t3.id = t1.id
WHERE t1.date >= NOW();
An explicit join, but further illustrates the relationship the tables must have when collecting data from different sources.

Related

MySQL: If a column value is 2 THEN do X ELSE do Y

The database I am working on right now is somewhat messy. I have three potential tables, that I want to join but in some cases it may only be two tables.
Let's call these table1, table2 and table3.
table1 has a field called "type". If table1.type is 2, then I only need to join table3.
For any other values I want to join table2 and then table3.
How can I achieve this in one single SQL query rather than: 1) having one query to select the type. 2) make a PHP foreach-loop to check the type of the current iteration and 3) perform a new query according to the type value.
Edit:
I'll try to be more specific.
table1 has a column named "pid" that references to a whole other table, but that's redundant to this question. I tried working my ways around with UNIONs and LEFT JOINs but couldn't manage to achieve what I was looking for.
I want to select all results from my database with the "pid" value being "100". This gives me four rows in return, where was 2 of them are of type value "2" and the others are "1".
So basically what I want to achieve is the following two SQL statements in one:
(If "type" is "2")
SELECT *
FROM table1 t1
INNER JOIN table3 t3
ON t1.id = t3.t1_id
WHERE t1.pid = 100
(If "type" is NOT "2")
SELECT *
FROM table1 t1
INNER JOIN table2 t2
ON t1.id = t2.t1_id
INNER JOIN table3 t3
ON t2.id = t3.t2_id
WHERE t1.pid = 100
I'm guessing I could manage to do this with a UNION statement, but I'm confused on how to implement the WHERE t1.pid = '100' part.
use an UNION e.g.
SELECT t1.*, t3.*
FROM table1 t1
INNER JOIN table3 t3 ON t1.id = t3.t1_id
WHERE t1.pid = 100 and t1.type = 2
UNION
SELECT t1.*, t3.*
FROM table1 t1
INNER JOIN table2 t2
ON t1.id = t2.t1_id
INNER JOIN table3 t3 ON t2.id = t3.t2_id
WHERE t1.pid = 100 and t1.type <> 2;
but it would be better to explicitly name the columns you want to get back.

Join tables on missing matched rows from the second table

I have two database tables - table1 and table2. For some records in table1 i have several rows connected in table2. For most of them i have 3 rows connected, but for some of them i have an extra row with a column value like table2.field='correct'. How can i join table1 and table2 if i want the result to return only the rows from table1 where there is no row in table2 with column value like table2.field='correct' connected to them ? Counting the number of rows from the second table( if num of connected rows < 4 or something like that is not an option).
I tried something like :
SELECT t1.* FROM table1 t1 LEFT JOIN table2 t2 on t1.id=t2.id_t1 WHERE t2.field IS NULL
but it did not work ofc. because i always have rows with value in field column. For each row in t1 that is connected to t2 i have record rows in t2 where t2.filed='name' and t2.field='type'. I need the rows from t1 that do not have a row connected to them in t2 where t2.field='correct'.
Use NOT IN
SELECT * from t1 WHERE t1.id NOT IN(SELECT id FROM t2 WHERE t2.field = 'correct')
$sql = "SELECT t1.* FROM table1 t1 CROSS JOIN table2 t2 on t1.id=t2.id_t1 WHERE t2.field IS NULL ";
SELECT t1.* FROM table1 t1 WHERE NOT EXISTS (SELECT t2.* FROM table2 t2 WHERE t1.id=t2.id_t1 AND t2.field = 'correct')

To find realted data of table1 in table2

Table1 Has Some data as Categories
Table2 Has Some data Which is Realated to table1 Categories
and the relation between two tables is cat_id from table1 and cat_ids from table2.
What I want is?
I need to display all fields in table1 and from table2 I need only the related content i.e id's present in cat_id(table1) and cat_ids(table2)
I am using a query like this select c.* ,cc.* from news_categories cc, news_content c where cc.cat_id = c.cat_ids group by cc.cat_id this gives only common data from table1 and table2.. i need common data and all categories from table1
can anyone help me?
You should use JOIN instead.
SELECT t1.*, GROUP_CONCAT(t2.content_id)
FROM table1 t1
LEFT JOIN table2 t2
ON t2.cat_ids = t1.cat_id
GROUP BY t1.cat_id
This is for all fields of both tables...
SELECT Table1.*, Table2.*
FROM Table1, Table2
WHERE Table1.cat_id = Table2.cat_ids
This is for all fields of Table1 and Content field of Table2...
SELECT Table1.*, Table2.full_content
FROM Table1, Table2
WHERE Table1.cat_id = Table2.cat_ids
you need to use outer join and this case left join .. Have a look at Documentation

Double tables select show?

I have a problem...I have 2 tables, Table1 and Table2.
Table1:
id,int(11)
text,varchar(11)
Table2:
id,int(11)
agentid,int(11)
unique(id,agentid)
Table2 has many id and agent ids in it. The data for the id in table 2 came from table 1.
I have an agentid say $aid. This has many id's associated with it in table 2.
I am trying to get the set of text values out from table 1 associated with all ids which are related to agentid $aid from table 2.
Does that make sense?!
Any ideas?
select text from table1 where id in
(
select id from table2 where agentid = <your aid>
)
This will give you all text rows for given agentid.
The same can be done using join too -
select t1.text from table1 t1
inner join table2 t2
on t1.id = t2.id
where t2.agentid = <your aid>
select * from table1 as t1 inner join table2 as t2
on t1.id = t2.id
where agentid = $aid
The query:
$sql = "select t1.text from table1 t1, table2 t2 where t2.id = t1.id and t2.agentid = {$aid}";
Try not to include the $aid directly in the query, but escape it and/or use prepared statements with query parameters.

Bulding a query of three tables in mysql

I have to three table I need to gather data from in a search process:
Commissions Table - Table1: [affiliate_id]
Affiliates Table - Table2: [id][user_id]
Profiles Table - Table3: [ID][NickName]
The search input I'll have is someone searched for a username. I need to return the data from table 1 where the affiliate_id matches the user_id of Table2, that is like the nickname that will be searched for.
I hope that makes sense :)
Try this:
"select table1.* from table1
inner join table2 on table2.user_id = table1.affiliate_id
inner join table3 on table3.id = table2.user_id
where table3.nickname like '%".mysql_real_escape_string($searchtext)."%'"
SELECT t1.*, t3.nickname FROM Table1 t1
JOIN Table2 t2 ON t2.id=t1.affiliate_id
JOIN Table3 t3 ON t2.user_id=t3.user_id
WHERE t2.user_id=?;

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