Menu
  • HOME
  • TAGS

Is there a way to create a primary key and have it cascade into other tables without re-entering data into the new tables?

Tag: mysql,database,cascade

I am working on setting up a database and have created tables that cascade out like using the cascade on update for the foreign key. I have two tables being worked with to try to solve this. My tables are like this:

create table Item(Item int(4) not null, EquipName varchar(20), Equip int(4) 
not null, primary key(Item, Equip))

create table Cross(Time timestamp default now(), Cross varchar(10) default 
'null', Item int(4) not null, Equip int(4) not null, Stop varchar(20) default 
'null', foreign key(Item, Equip) references Item(Item, Equip) on update 
cascade);

So I want to be able to enter data into the Item table and have it be automatically put into Cross table where those values are cascaded to. This is why Cross and StopCount have a default value of null.

For example insert into Item values(5, fan, 4); I would like Cross to be populated in the FK spots automatically to what information was entered into Item.

Best How To :

You can use a trigger to autofill another table.

DELIMITER $$
CREATE TRIGGER init_cross AFTER INSERT ON item
  FOR EACH ROW
  BEGIN
    INSERT INTO `cross`(item,equip) VALUES( NEW.item, NEW.equip );
  END;
$$
DELIMITER ;

how will i order this query by DoctorName

php,mysql

Add an ORDER BY statement to your query: $q=mysqli_query($link,"Select * from doctor where status='". $stat ."' ORDER BY `doctor_last_name`"); ...

SQL Group By multiple categories

php,mysql,sql,mysqli

Just include a case statement for the group by expression: SELECT (CASE WHEN Categories.name like 'Cat3%' THEN 'Cat3' ELSE Categories.name END) as name, sum(locations.name = 'loc 1' ) as Location1, sum(locations.name = 'loc 2') as Location2, sum(locations.name = 'loc 3') as Location3, count(*) as total FROM ... GROUP BY (CASE...

How to search images by name inside a folder?

php,mysql,image

This looks like a job for glob, which returns an array of file names matching a specified pattern. I'm aware of the other answer just posted, but let's provide an alternative to regex. According to the top comment on the docs page, what you could do is something like this:...

How to create multiple jquery form fields and insert in mysql database, without using mysql_real_escape_string

javascript,php,jquery,mysql

Your problem has nothing to do with jQuery and the form. It is just highly recommended to prevent SQL injection, an attack in which an attacker injects SQL commands into your DB Query by posting it in your form. That's why any data that comes from an untrusted source (eg...

C# MySQL Parameters.AddWithValue

c#,mysql

You try to add all your 52 parameter and their values with one AddWithValue method. You can't do that. First of all, you need to define all your parameters in your command with your column names like; command.CommandText = "INSERT INTO tb_mitarbeiter (Vorname, id, projectnummber....) VALUES (?name, ?id, ?projektnummer....)"; Then...

IBM Cognos _days_between function not working

mysql,database,date,cognos

The Cognos _days_between function works with dates, not with datetimes. Some databases, like Oracle, store all dates with a timestamp. On a query directly to the datasource, try using the database's functions to get this data instead. When possible, this is always preferable as it pushes work to the database,...

Temporarily Number Rows to Group by in MYSQL

mysql

You can do this using variables: select s.*, floor( ((@rn := @rn + 1) - 1) / 5) as group_number from sample s cross join (select @rn := 0) params order by date; ...

If I export my database with phpmyadmin will it lock my tables or take my database down?

mysql,database,phpmyadmin

The answer is no, tables won't be locked, database won't be down. But, if your database is large and it takes long time to backup it, you can sometimes expect performance degradation(slow SQL queries from your application).

How to program a recurring billing/invoice system using PHP and MySQL

php,mysql

Cron sounds good. (Also it is worth to mention the MySQL Event Scheduler, but again I would go for a Cronjob) A copy would be something like this SQLFIDDLE: create table t ( id int, d date ); insert into t values( 0, CURDATE() ); insert into t values( 2,...

What type of database is the best for storing array or object like data [on hold]

database,node.js,sockets

Redis would probably be fastest, especially if you don't need a durability guarantee - most of the game can be played out using Redis' in-memory datastore, which is probably gonna be faster than writing to any disk in the world. Perhaps periodically, you can write the "entire game" to disk....

Inner Join 3 tables pl/sql

mysql,sql

The issue is that you are using the alias C where you should not, with the count function. This: C.Count(C.column6) should be: Count(C.column6) and the same change applies in the order by clause (which might be counting the wrong column - should it not be column6?): order by C.count(column5) desc...

mysql detect field value change

mysql

Here's a way to do it using variables: SELECT id, `timestamp`, ver_fw FROM ( SELECT id, `timestamp`, ver_fw, IF ( @prev_ver <> ver_fw, IF (@prev_ver := ver_fw, 1, 1), IF (@prev_ver := ver_fw, 0, 0)) AS IsDifferent FROM tbl_geodata CROSS JOIN (SELECT @prev_ver := '-1') AS var WHERE imei LIKE...

Foreign key in C#

c#,sql,sql-server,database

You want create relationship in two table Refer this link http://www.c-sharpcorner.com/Blogs/5608/create-a-relationship-between-two-dataset-tables.aspx...

concatenate field names in a mysql update with inner join

php,mysql

You can try as per below- UPDATE products pr INNER JOIN sub_categories sc ON sc.id = pr.sub_category SET slug = REPLACE(TRIM(LOWER(CONCAT(sc.subcat_name,'.',products.product_name))),' ', '-'); ...

Having two arrays in variable php

php,mysql,arrays,variables,multidimensional-array

The explode function is being used correctly, so your problem is further up. Either $data[$i] = mysql_result($result,$i,"data"); isn't returning the expected string "2015-06-04" from the database OR your function $data[$i] = data_eng_to_it_($data[$i]); isn't returning the expected string "04 June 2015" So test further up by echo / var_dump after both...

How to call MySQL view in Struts2 or Hibernate

java,mysql,hibernate,java-ee,struts2

You can simply create an Entity, that's mapping the database view: @Entity public class CustInfo { private String custMobile; private String profession; private String companyName; private Double annualIncome; } Make sure you include an @Id in your view as well, if that's an updatable view. Then you can simply use...

PHP / MySQLi: How to prevent SQL injection on INSERT (code partially working)

php,mysql,mysqli,sql-injection,sql-insert

In the New PHP code snippet, you are still vulnerable to injections. You are using a prepared statement in the insert part, but you are not actually using the preparations strengths correctly. When creating a prepared statement, you create a query in which you add placeholders instead of the raw...

Fatal error in if stament [duplicate]

php,mysql,mysqli

Just change the condition to: if(isset($_REQUEST['userid']) && $_REQUEST['userid'] > $user_hack) isset tells is a variable is set, while this statement may be true or false, on which you cannot call isset function. Until you check if(isset($_REQUEST['userid'])), you cannot assign it to $userid variable....

Query how often an event occurred at a given time

mysql,sql

This could be done using user defined variable which is faster as already mentioned in the previous answer. This needs creating incremental variable for each group depending on some ordering. And from the given data set its user and date. Here how you can achieve it select user, date, purchase_count...

MySQL substring match using regular expression; substring contain 'man' not 'woman'

mysql,regex

A variant of n-dru pattern since you don't need to describe all the string: SELECT '#hellowomanclothing' REGEXP '(^#.|[^o]|[^w]o)man'; Note: if a tag contains 'man' and 'woman' this pattern will return 1. If you don't want that Gordon Linoff solution is what you are looking for....

How do I display my mysql table column headers in my php/html output?

php,html,mysql,table,data

Note: You can just make a single file out of it to achieve your wanted output Use mysql_real_escape_string() to sanitize the passed-on value to prevent SQL injections You should use mysqli_* instead of the deprecated mysql_* API Form them in a single file like this (display.php): <html> <form method="post" name="display"...

Can Rails deal with DB uniqueness without index?

mysql,ruby-on-rails,rdbms

Because there is no need for other ways. Under the hood it's all the same: when you define a UNIQUE constraint, a UNIQUE index is created on that table to enforce it. Question from DBA.SE: When should I use a unique constraint instead of a unique index? So for a...

Symfony2 creating and persisting entity relationships

php,mysql,symfony2,doctrine2

When you create two entities with a one-to-one relationship, both entities need to be persisted either explicitly or by using cascade persist on one side of the relationship. You also need to explicitly set both sides of the relationship. Doctrine - Working with Associations - Transitive persistence / Cascade Operations...

Purging Database - Count purged/not-purged tables

mysql,sql,sql-server,database,stored-procedures

The only way to do this is to manually run a count(*) on all of your tables filtering on the particular date field. The reason for this is because one table might have a column "CreatedDate" that you need to check if it's >30 days old, while another might have...

Retrieve Values As Column

mysql,sql

If types are fixed (just IMPRESSION and CLICK), you could use a query like this: SELECT headline, SUM(tracking_type='IMPRESSION') AS impressions, SUM(tracking_type='CLICK') AS clicks FROM tracking GROUP BY headline ...

Using VLOOKUP formula or other function to compare two columns

mysql,excel,vba,date

If data in your first table starts at A2, and your other column starts at D2, then use in E2 =VLOOKUP(D2,$A$2:$B$17,2,0) Copy down as needed....

Notice: Array to string conversion in “path of php file” on line 64

php,mysql,arrays,oracle

Curly brackets are your friend when inserting variables into double quoted strings: $main_query=oci_parse($connection,"INSERT INTO ROTTAN(NAME,ROLLNO) VALUES('{$array[$rs][0]}','{$array[$rs][1]}')"); ...

MySQLdb Python - Still getting error when using CREATE TABLE IF NOT EXISTS

python,mysql

MySQL is actually throwing a warning rather that an error. You can suppress mysql warnings like this : import MySQLdb as mdb from warnings import filterwarnings filterwarnings('ignore', category = mdb.Warning) Now the mysql warnings will be gone. But mysql errors will be shown as usual Read more about warnings at...

I Want to fetch SQL Records in MySQL of current Year

mysql

Try this: SELECT count(enq.`enquiryId`), Month(enq.`date`), Year(enq.`date`) FROM enquiry enq WHERE Year(enq.date)=somevalue --2015 for example GROUP BY MONTH(enq.`date`) ...

MySQL - How can I know my query is tuned?

mysql,performance,explain

Except for trivial queries, there is no way to know if you have the optimal query & indexes. Nor can you get a metric for how well designed the schema and application are. 3 seconds on a cold system for a 3-way JOIN with "Rows" of 409, 45, 1 is...

Trying to rewrite mysql_* to pdo

php,mysql,pdo

I don't know the source of the array $arr = array();, but it is assigned to null before the insert query. So it means, literally you are inserting nothing into the database. So check your array well, maybe it was to be like $arr = array('name'=>'My Name', 'url'=>'url', 'email'=>'my email',...

Ignore Group if LIMIT is not reached in MySQL

mysql

You can use the having clause to filter out the groups you don't need, keeping only the groups where there are more than 4 dates: SELECT Fruits, SUM(Ordered), Date FROM table GROUP BY Date HAVING COUNT(Date) > 4 ...

Why am getting this error?: Unknown column 'firstname' in 'field list'

php,database,mysqli

$query = "INSERT INTO `myDatabaseForAll`.`users` (`id`, `firstname`, `lastname`, `username`, `password`) VALUES (NULL, $firstname, $lastname,$username,$password)"; you need single quote around text feilds in sql queries change above query to $query = "INSERT INTO `myDatabaseForAll`.`users` (`id`, `firstname`, `lastname`, `username`, `password`) VALUES (NULL, '$firstname', '$lastname','$username','$password')"; ...

MySQL trigger help, capturing a variable from php insert into

php,mysql,triggers

You are on the right path: IF (SELECT true FROM redcap_encryption WHERE ProjectID=NEW.project_id AND FieldName=NEW.field_name).... ...

PHP: While loop not working after adjusting SELECT for SQL injection prevention

php,mysql,select,sql-injection,associative-array

You cannot bind column and table names, only data. You need to specify the table and then bind for your '%calendar weekday%'. $stmt = $conn->prepare("SELECT " . $selectLang . " FROM `TranslationsMain` WHERE `location` LIKE ? ORDER BY `sortOrder`, " . $selectedLang); $stmt->bind_param('s', $calendar_weekday); ...

How do I find records in one table that do exist in another but based on a date?

mysql,sql

select d.`name` from z_dealer d where (select count(*) from z_order o WHERE o.promo_code = d.promo_code AND o.date_ordered > '2015-01-01') = 0 ...

Creating a generic / abstract “DBContext” Class for shared functionality among different DBs

c#,database,generics,inheritance,abstract-class

The key here is to step back and think about the problem from another angle. You are duplicating lots of code because you are creating instances of the database and command classes within the method. So inject them instead: public class SomeDBClass { static DataTable exec_DT(DBConnection conn, DBCommand cmd) {...

SQLite: Individual tables per user or one table for them all?

database,sqlite

In an object oriented language, would you make a class for every user? Or would you have an instance of a class for each user? Having one table per user is a really bad design. You can't search messages based on any field that isn't the username. With your current...

MySQL: Select several rows based on several keys on a given column

mysql,sql,database

If you are looking to find the records matching with both the criteria here is a way of doing it select `item_id` FROM `item_meta` where ( `meta_key` = 'category' and `meta_value` = 'Bungalow' ) or ( `meta_key` = 'location' AND `meta_value` = 'Lagos' ) group by `item_id` having count(*)=2 ...

Using Sum in If in Mysql

mysql,sql,select,sum

Using least would be much easier: SELECT LEAST(SUM(my_field), 86400) FROM my_table ...

Pull information from SQL database and getting login errors

php,sql,database

change $username = "'rylshiel_order"; to $username = "rylshiel_order"; and you should be through. You are passing on an extra single quote here. ...

compare today's date with unix timestamp value in database

php,mysql

If I understand correctly you have a unix timestamp in a varchar field and you can't change this. If you compare the unix timestamp directly you will only get results that match the exact second of the timestamp. You can use FROM_UNIXTIME() to convert the timestamp in a date value...

Php Mysql Query not working properly

php,mysql

No need to use union as it will give a lots of duplicate data What you want to achieve can be done with simple left join or inner join SELECT m.issue_name ,m.issue_type , m.priority ,m.status,m.description , m.start_date,m.end_date,m.duration, s.name as server_name,p.name as product_name from mod_networkstatus as m LEFT JOIN tblservers as...

C# - Can't connect to remote MySQL server

c#,mysql

When connecting to a MySQL-Database I always used the MySQL Connector you can get here: https://dev.mysql.com/downloads/connector/net/6.9.html You have to import the MySQL namespaces to your project and then you can use the MySQLConnection instead of the SQLConnection that is, as far as I know, only for MSSQL servers. http://www.codeproject.com/Tips/423233/How-to-Connect-to-MySQL-Using-Csharp...

Select most recent entry where timestamp is from the past hour

mysql

select * from table where TIMESTAMPDIFF(HOUR, `timestamp`, NOW())=0 ORDER BY `timestamp` DESC LIMIT 1 ...

MySQL Query returning strange values

php,mysql

You need to join by account_id and also question_id SELECT * FROM `quiz_questions` INNER JOIN `quiz_answers` ON `quiz_questions`.`account_id` = `quiz_answers`.`account_id` AND `quiz_questions`.`question_id` = `quiz_answers`.`question_id` WHERE `quiz_questions`.`account_id` = '1840979156127491' ORDER BY `quiz_questions`.`question_id` ASC LIMIT 5 ...