I have 2 tables named "rel_eq" and "rel_cat". From the table "rel_cat" I need to compare the id with the column "relcat" in the table "rel_eq". And I need to select all columns from both tables so that I can output in a loop. In some lines in the "rel_eq" table, there is no value in the relcat column. I need to make sure there is either no value where it is missing, or a default, like "uncategory". My code $eq_arr = $wpdb->get_results("SELECT * FROM $table_name CROSS JOIN $table_cat"); but I have to sort through all the id and assign the same id from another table. Please tell me how to do this.
You will need to run the following:
$eq_arr = $wpdb->get_results("SELECT * FROM rel_eq join rel_cat on rel_eq.relcat = rel_cat.id");
If you want a record even when there is no match, use INNER JOIN and handle the problem in your cycle.
Related
I have 2 tables, a users table and a trade table.
Which look like:
The structure of my code right now is:
<?php
$history = mysqli_query($con, "SELECT * FROM .......");
while($row = mysqli_fetch_array($history)) {
echo("The sentence");
} ?>
Problem I'm facing is that I'm trying to echo the user_name which in one case has to be the receiver and other the person giving it.
Pro tip: Never use SELECT * in software unless you know exactly why you are doing so. In your case it is harmful.
I'm assuming your query is really against the user and trade tables you mentioned in your question.
First, recast your query using 21st century SQL, as follows:
SELECT *
FROM trade AS t
JOIN user AS s ON s.user_id = t.user_id_sender
WHERE s.facebook_id = $fbid
Second, use this to retrieve your user's names and the item id traded.
SELECT s.user_name AS sender,
r.user_name AS receiver,
t.trade_id AS item_id
FROM trade AS t
JOIN user AS s ON s.user_id = t.user_id_sender
JOIN user AS r ON r.user_id = t.user_id_receiver
WHERE s.facebook_id = $fbid
See how we JOIN the user table twice, with two different aliases s (for sender) and r (for receiver)? That's the trick to fetching both names from IDs.
See how we employ the aliases sender and receiver to disambiguate the two user_name columns in the result set?
Now, when you use the php fetch_array function, you'll end up with these elements in the array.
$history['sender']
$history['receiver']
$history['item_id']
The array index strings correspond to the alias names you specified in your SELECT clause in your query.
So, one reason to avoid SELECT * is that you can get more than one column with the same name, and that means fetch_array will eliminate those duplicates and so it will lose useful information from your result set.
I am building a site and i need to retrieve some information. I have this query.
$SQL = "SELECT distretto_108, provinca_113, regioni_116, tipologia_pdv_106,
richiesta_ccnl_107, coop_va_109, nome_pdv_110,
indirizzo_pdv_111, localita_112
FROM civicrm_value_informazioni_su_tute_le_schede_p_22 ";
I need to add this other code:
WHERE civicrm_event.title_en_US='".addslashes($_GET["titles"])."'
but it's not working...
i need to compare let's say the id of another table with the id of the current table... How to do that?
Thanks in advance...
You should learn something about joining tables...
Do not know what the relation is between the two tables (simply said: what column from one table is pointing to what column at other one), but try something similar (modification needed to meet You DB structure) - now lets assume both tables have related column called event_id:
$SQL = "SELECT distretto_108, provinca_113, regioni_116, tipologia_pdv_106,
richiesta_ccnl_107, coop_va_109, nome_pdv_110,
indirizzo_pdv_111, localita_112
FROM civicrm_value_informazioni_su_tute_le_schede_p_22 cvistlsp22
LEFT JOIN civicrm_event ce ON ce.event_id = cvistlsp22.event_id
WHERE ce.title_en_US='".mysql_real_escape_string($_GET["titles"])."'";
civicrm_value_informazioni_su_tute_le_schede_p_22 table name is very long and You will not be able to create a table with such long name in other DBMS (e.g. ORACLE), so try to make it shorter while still self-describing...
If You want to join tables they have to have a relation, read more about relations and how to use them here: http://net.tutsplus.com/tutorials/databases/sql-for-beginners-part-3-database-relationships/
You are retrieving the data from table civicrm_value_informazioni_su_tute_le_schede_p_22 in your query while the where clause you are adding, refers to the table civicrm_event. You need to add this new table in the from clause and do a join among the two tables using some common key. Example below:
$SQL = "
SELECT distretto_108, provinca_113, regioni_116, tipologia_pdv_106, richiesta_ccnl_107, coop_va_109, nome_pdv_110, indirizzo_pdv_111, localita_112
FROM civicrm_value_informazioni_su_tute_le_schede_p_22
JOIN civicrm_event ON civicrm_value_informazioni_su_tute_le_schede_p_22.ID_PK = civicrm_event.ID_FK
WHERE civicrm_event.title_en_US='".addslashes($_GET["titles"])
";
You need to replace the ID_PK and ID_FK with the relevant Primary and Foreign Keys that bind the tables together.
Please note using query params like that is not recommended. Please read PHP Documentation here for more explanation.
I have a table for users. But when a user makes any changes to their profile, I store them in a temp table until I approve them. The data then is copied over to the live table and deleted from the temp table.
What I want to achieve is that when viewing the data in the admin panel, or in the page where the user can double check before submitting, I want to write a single query that will allow me to fetch the data from both tables where the id in both equals $userid. Then I want to display them a table form, where old value appears in the left column and the new value appears in the right column.
I've found some sql solutions, but I'm not sure how to use them in php to echo the results as the columns in both have the same name.
Adding AS to a column name will allow you to alias it to a different name.
SELECT table1.name AS name1, table2.name AS name2, ...
FROM table1
INNER JOIN table2
ON ...
If you use the AS SQL keyword, you can rename a column just for that query's result.
SELECT
`member.uid`,
`member.column` AS `oldvalue`,
`edit.column` AS `newvalue`
FROM member, edit
WHERE
`member.uid` = $userId AND
`edit.uid` = $userId;
Something along those lines should work for you. Although SQL is not my strong point, so I'm pretty sure that this query would not work as is, even on a table with the correct fields and values.
Here is your required query.
Let suppose you have for example name field in two tables. Table one login and table 2 information. Now
SELECT login.name as LoginName , information.name InofName
FROM login left join information on information.user_id = login.id
Now you can use LoginName and InofName anywhere you need.
Use MySQL JOIN. And you can get all data from 2 tables in one mysql query.
SELECT * FROM `table1`
JOIN `table2` ON `table1`.`userid` = `table2`.`userid`
WHERE `table1`.`userid` = 1
I have two tables, one that has a foreign key from the other. I want to get all records that don't exist in the foreign table, based on certain criteria.
Here are the tables I have:
item_setting
setting_id
category_id
item
item_id
setting_id
name
expired_dt
Here's the query I'm using now:
SELECT
iset.setting_id
FROM
item_settings iset
LEFT OUTER JOIN
item i ON i.setting_id = iset.setting_id
WHERE
iset.category_id = '5' AND i.setting_id is null
This query works in providing any setting_id's that do not have a record in the item's table within a specific category.
However, now I want to include cases where the expired_dt less than than time() (meaning it's past expired). In otherwords, I would think to add this:
WHERE
iset.category_id = '5' AND (i.setting_id is null OR i.expired_dt < '".time()."')
However, this doesn't work, it returns all the records.
Any suggestions? Maybe I'm completely over complicating this.... I just want to return the setting_id's from the item_settings table, where the expired_dt associated in the item table is expired or if it does not even exist in the item table.
Thank you!
Try moving the timestamp condition into the join clause. Something like
item_settings iset
LEFT OUTER JOIN
item i ON i.setting_id = iset.setting_id and i.expired_dt > time()
I had my query set up the other day as so
$query = "SELECT card_id,title,description,meta_description,seo_keywords,price
FROM cards,card_cheapest order by card_id";
As you can see, I was selecting card_id,title,description,meta_description,seo_keywords from the table cards, and price was coming from cheapest_card. They both have the card_id in common (in both tables). However, I ran into a bit of an issue. When I run the query in navicat lite, I receive an error "card_id is ambiguous". Was I doing something wrong?
When 2 or more tables have a column that is named the same, you have to qualify the table you want the column to be from.
i.e.:
$query = "SELECT cards.card_id,title,description,meta_description,seo_keywords,price
FROM cards,card_cheapest order by card_id";
Furthermore, do you really want to run the query this way, without a WHERE/JOIN-clause to define how to JOIN the two tables?
$query = "SELECT cards.card_id,title,description,meta_description,seo_keywords,price
FROM cards,card_cheapest WHERE cards.card_id = card_cheapest.card_id
ORDER BY card_id";
When you have the same column name in two tables you're selecting from, you have to prefix the part in the SELECT with one of the table names (it doesn't matter which if it's the same data)
such as SELECT cards.card_id, ...
EDIT: However, cularis's answer is much more explanatory than mine, and take note about joining the two card_id columns if you want to get correct results.
When you run queries that get information from multiple tables with shared field names you need to specify from which table you want to extract what field. You do this by specifying the table name before the field name.
In your case you have two options:
cards.card_id or card_cheapest.card_id.
Also I agree with #cularis, you are probably better of doing a join, but still you will need to specify which card_id you want to select: the one from cards or card_cheapest.