Search Results

Search found 40744 results on 1630 pages for 'sql interview questions a'.

Page 715/1630 | < Previous Page | 711 712 713 714 715 716 717 718 719 720 721 722  | Next Page >

• MYSQL to UPDATE table if row with 2 specific columns exist or INSERT new row if it does not exist

  - by user2509541

  I have a MYSQL table that looks as follows: id id_jugador id_partido team1 team2 1 2 1 5 2 2 2 2 1 1 3 1 2 0 0 I need to create a query to either INSERT new rows in the table or UPDATE the table. The condition is based on id_jugador and id_partido, meaning that if I wanted to insert id_jugador = 2 and id_partido = 1, then it should just UPDATE the existing row with the new team1 and team2 values I am sending. And dont duplicate the row. However, if I have an entry id_jugador=2 and id_partido=3, since this combination does not exist yet, it should add the new row. I read about the REPLACE INTO but it seems to be unable to check combination of UNIQUE KEYS.

  Read the article

• How can I treat a sequence value like a generated key?

  - by Jeff Knecht

  Here is my situation and my constraints: I am using Java 5, JDBC, and DB2 9.5 My database table contains a BIGINT value which represents the primary key. For various reasons that are too complicated to go into here, the way I insert records into the table is by executing an insert against a VIEW; an INSTEAD OF trigger retrieves the NEXT_VAL from a SEQUENCE and performs the INSERT into the target table. I can change the triggers, but I cannot change the underlying table or the general approach of inserting through the view. I want to retrieve the sequence value from JDBC as if it were a generated key. Question: How can I get access to the value pulled from the SEQUENCE. Is there some message I can fire within DB2 to float this sequence value back to the JDBC driver?

  Read the article

• how to check if a combobox is empty without setfocus?

  - by every_answer_gets_a_point

  i need to know if any text has been entered into a combobox if i do: If comboReason1.Value <> "" Then it gives me an error, and if i do: If comboReason1.Value <> Null then this doesn't work. how do i check whether text has been entered into the combobox?

  Read the article

• Can I lock rows in a cursor if the cursor only returns a single count(*) row?

  - by RenderIn

  I would like to restrict users from inserting more than 3 records with color = 'Red' in my FOO table. My intentions are to A) retrieve the current count so that I can determine whether another record is allowed and B) prevent any other processes from inserting any Red records while this one is in process, hence the for update of. I'd like to do something like: cursor cur_cnt is select count(*) cnt from foo where foo.color = 'Red' for update of foo.id; Will this satisfy both my requirements or will it not lock only the rows in the count(*) who had foo.color = 'Red'?

  Read the article

• Check if db connection is closed - php

  - by Hamad

  Db connectivity is handled by an include. I want to run this command: mysql_close($con); Only if we currently have a connection. Something like isset()? Thanks Hamad

  Read the article

• Design pattern for data entry forms with LINQ2SQL

  - by petebob796

  I am about to start a new winforms data entry application, it already has the database designed which I am comfortable with. I was going to use LINQ2SQL to access the tables to keep things type safe but am now wondering about design patterns, something I am just getting into. Since LINQ is giving me objects to use should I still create classes in between to hold the validation code and helper methods or should these just go in with the UI? It just seems I will end up with classes sat in between with little code which will cause the UI classes to have code just getting and setting values in the intermediate class and returning from validation to flag errors... Any good reading on this? Should I consider the entity framework (or similar) instead?

  Read the article

• Oracle Sql: how to substract rows from one table from another only once

  - by slyder07

  I'm working for a university project, and I have the following question: I have 2 tables in a Oracle DB... I need to select those rows from table1, which are not included in table2... But the main problem is that I need to exclude that rows from table2 wich was selected once... For example: Table1 Table2 ResultTable id | Number | Letter id | Number | Letter id | Number | Letter _____________________ _____________________ _____________________ 1 4 S 1 6 G 2 2 P 2 2 P 2 8 B 3 5 B 3 5 B 3 4 S 4 4 S 4 4 S 4 1 A 6 2 P 5 1 A 5 1 H 6 2 P 6 2 X So, how you see it, if one row from Table1 has a "twin" in Table2, they both are excluded. Hope I was explicit enough. Sorry for my bad English. Thanks.

  Read the article

• SqlCeCommand ExecuteNonQuery performance issue

  - by Michael

  I've been asked to resolve an issue with a .Net/SqlServerCe application. Specifically, after repeated inserts against the db, performance becomes increasingly degraded. In one instance at ~200 rows, in another at ~1000 rows. In the latter case the code being used looks like this: Dim cm1 As System.Data.SqlServerCe.SqlCeCommand = cn1.CreateCommand cm1.CommandText = "INSERT INTO Table1 Values(?,?,?,?,?,?,?,?,?,?,?,?,?)" For j = 0 To ds.Tables(0).Rows.Count - 1 'this is 3110 For i = 0 To 12 cm1.Parameters(tbl(i, 0)).Value = Vals(j,i) 'values taken from a different db Next cm1.ExecuteNonQuery() Next The specifics aren't super important (like what 'tbl' is, etc) but rather whether or not this code should be expected to handle this number of inserts, or if the crawl I'm witnessing is to be expected.

  Read the article

• connection mssql with qt

  - by ayla

  How can I connect mssql with Qt ? Thank a lot.

  Read the article

• How to use "contains" or "like" in a dynamic linq query?

  - by Curtis White

  The help file that came with Dynamic Linq in the CSharpSamples.zip does not show any examples of using contains or like. Are there any simple workarounds for doing this? i.e where (col like @col) doesn't work.

  Read the article

• select row from table and substitute a field with one from another column if not null

  - by EarthMind

  I'm trying construct a PostgreSQL query that does the following but so far my efforts have been in vain. Problem: There are two tables: A and B. I'd like to select all columns from table A (having columns: id, name, description) and substitute the "A.name" column with the value of the column "B.title" from table B (having columns: id, table_A_id title, langcode) where B.table_A_id is 5 and B.langcode is "nl" (if there are any rows). I've tried using a CASE and COALESCE() but failed due to my inexperience with both concepts. Thanks in advance.

  Read the article

• count(*) vs count(column-name) - which is more correct?

  - by bread

  Does it make a difference if you do count(*) vs count(column-name) as in these two examples? I have a tendency to always write count(*) because it seems to fit better in my mind with the notion of it being an aggregate function, if that makes sense. But I'm not sure if it's technically best as I tend to see example code written without the * more often than not. count(*): select customerid, count(*), sum(price) from items_ordered group by customerid having count(*) > 1; vs. count(column-name): SELECT customerid, count(customerid), sum(price) FROM items_ordered GROUP BY customerid HAVING count(customerid) > 1;

  Read the article

• Mysql query to fetch data

  - by hnihar

  i have a table "request" with 4 columns namely: 1.recId :long primary key 2.interactionId:long 3.requestedBy:boolean 4.requestedType:boolean and data is as follows: VALUES (185,455699,0,5), (186,455746,0,1), (187,455746,1,1), (188,455752,0,1), (189,455753,0,1), (190,455753,1,1), (191,455754,1,1) i want a query to fetch all the rows where interactionId is same and having requestedBy both 1 and 0 values and requestType=1; regards, Nihar

  Read the article

• Is it possible to modify the value of a record's primary key in Oracle when child records exist?

  - by Chris Farmer

  I have some Oracle tables that represent a parent-child relationship. They look something like this: create table Parent ( parent_id varchar2(20) not null primary key ); create table Child ( child_id number not null primary key, parent_id varchar2(20) not null, constraint fk_parent_id foreign key (parent_id) references Parent (parent_id) ); This is a live database and its schema was designed long ago under the assumption that the parent_id field would be static and unchanging for a given record. Now the rules have changed and we really would like to change the value of parent_id for some records. For example, I have these records: Parent: parent_id --------- ABC123 Child: child_id parent_id -------- --------- 1 ABC123 2 ABC123 And I want to modify ABC123 in these records in both tables to something else. It's my understanding that one cannot write an Oracle update statement that will update both parent and child tables simultaneously, and given the FK constraint, I'm not sure how best to update my database. I am currently disabling the fk_parent_id constraint, updating each table independently, and then enabling the constraint. Is there a better, single-step way to update this content?

  Read the article

• Embedded analog of CouchDB, same as sqlite for SQL Server

  - by Mike Chaliy

  I like an idea of document oriented databases like CouchDB. I am looking for simple analog. My requirements is just: persistance storage for schema less data; some simple in-proc quering; good to have transactions and versioning; ruby API; map/reduce is aslo good to have; should work on shared hosting What I do not need is REST/HTTP interfaces (I will use it in-proc). Also I do not need all scalability stuff.

  Read the article

• Is it possible to insert multiple rows at a time in an SQLite database?

  - by Andrew

  In MySQL you can insert multiple rows like this: INSERT INTO 'tablename' ('column1', 'column2') VALUES ('data1', 'data2'), ('data1', 'data2'), ('data1', 'data2'), ('data1', 'data2'); However, I am getting an error when I try to do something like this. Is it possible to insert multiple rows at a time in an SQLite database? What is the syntax to do that?

  Read the article

• SSRS Performance Mystery

  - by user101654

  I have a stored procedure that returns about 50000 records in 10sec using at most 2 cores in SSMS. The SSRS report using the stored procedure was taking 20min and would max out the processor on an 8 core server for the entire time. The report was relatively simple (i.e. no graphs, calculations). The report did not appear to be the issue as I wrote the 50K rows to a temp table and the report could display the data in a few seconds. I tried many different ideas for testing altering the stored procedure each time, but keeping the original code in a separate window to revert back to. After one Alter of the stored procedure, going back to the original code, the report and server utilization started running fast, comparable to the performance of the stored procedure alone. Everything is fine for now, but I am would like to get to the bottom of what caused this in case it happens again. Any ideas?

  Read the article

• Date type in oracle does not include time values

  - by Matt

  I have a PHP application using an Oracle XE database. Whenever I add a date the hours minutes, and seconds seem to get left out. Is there some special format, or type I should use to be able to store this? I have tried using to_date, and specifying the format I am using. Many thanks for any suggestions from this confused MySql dveloper.

  Read the article

• What would be the fastest way to insert 750 records using Ado.NET?

  - by Lieven Cardoen

  We have tried it using an orm mapper tool, but it opens en closes the connection 750 times. Then we tried to construct a bulk insert, but that goes even slower...

  Read the article

• Crash when checking BOF property of pessimistic locked ADO recordset

  - by Patrick

  Bit of an odd one for you: I've got two connections to a database, on one I've opened a _RecordsetPtr with a pessimistic lock. I can no longer send an UPDATE command on the other connection. I can send a SELECT command on the second connection and data is returned. If I use a read only lock then there are no problems however when I use a pessimistic lock on the second connection as well I can check the State == adStateOpen but the program hangs when I test the BOF property! If I don't test the BOF property and try to call moveNext on the second connection the software hangs If I do neither of these I am able to access the data via the second connection but trying to access the data from the first connection causes the software to hang. Any one seen anything similar as I'm a bit stuck? EDIT : it wasn't hanging, someone had put a 30 minute timeout on the connection and I wasn't waiting that long while testing...

  Read the article

• How do you do bulk inserts using sqlapi++ ?

  - by varun

  i am using sqlapi++ library. does it support bulk inserts?

  Read the article

• Wanted: Good examples of Scala database persistence

  - by Rydell

  I'm would like to use Scala to persist data to a relational database, so what I am looking for are examples of CRUD operations using Scala. I would like to code on a lower level of abstraction than an ORM like Hibernate/Toplink (read:JDBC), but between us, I would like to see examples of all types. Thanks folks.

  Read the article

• have mysql select statement return fully qualified column names like table.field

  - by handsomeGun

  is there a way to have a mysql select statement return fully qualified column names like "table.field" without using AS for every single field? like so: SELECT * FROM table1 LEFT JOIN table2 on table1.f_ID = table2.ID and the result would be: "table1.ID", "table1.name", "table2.ID", "table2.name", ...

  Read the article

• How to renumber primary index.

  - by Kamil Mroczek

  I have got a simple MySQL table and primary index (id) is not numbered one by one (1, 31, 35, 100 etc.). I want them to be numbered like (1, 2, 3, 4). Please tell me how to do it. I would also like to point that I am aware of possible consequences of the operation, but I just want to tidy up the table.

  Read the article

• How to filter rows on a complex filter

  - by dan

  I have these rows in a table ID Name Price Delivery == ==== ===== ======== 1 apple 1 1 2 apple 3 2 3 apple 6 3 4 apple 9 4 5 orange 4 6 6 orange 5 7 I want to have the price at the third delivery (Delivery=3) or the last price if there's no third delivery. It would give me this : ID Name Price Delivery == ==== ===== ======== 3 apple 6 3 6 orange 5 7 I don't necessary want a full solution but an idea of what to look for would be greatly appreciated.

  Read the article

< Previous Page | 711 712 713 714 715 716 717 718 719 720 721 722  | Next Page >