Search Results

Search found 53054 results on 2123 pages for 'sql sample database'.

Page 840/2123 | < Previous Page | 836 837 838 839 840 841 842 843 844 845 846 847  | Next Page >

  • Hash Join require Full Table Scan

    - by Pedro Magalhaes
    So, I want to know if to make a Hash Join between two tables is necessary to make a full table scan on the collumns? If i want to join COL1 wiht COL2, and COL1 is smaller, the It makes a full scan in COL1 creating a Hashmap then makes a full scan in COL2 using the sabe hash function. Is this correct?

    Read the article

  • Difference b/w putting condition in JOIN clause versus WHERE clause

    - by user244953
    Suppose I have 3 tables. Sales Rep Rep Code First Name Last Name Phone Email Sales Team Orders Order Number Rep Code Customer Number Order Date Order Status Customer Customer Number Name Address Phone Number I want to get a detailed report of Sales for 2010. I would be doing a join. I am interested in knowing which of the following is more efficient and why ? SELECT O.OrderNum, R.Name, C.Name FROM Order O INNER JOIN Rep R ON O.RepCode = R.RepCode INNER JOIN Customer C ON O.CustomerNumber = C.CustomerNumber WHERE O.OrderDate >= '01/01/2010' OR SELECT O.OrderNum, R.Name, C.Name FROM Order O INNER JOIN Rep R ON (O.RepCode = R.RepCode AND O.OrderDate >= '01/01/2010') INNER JOIN Customer C ON O.CustomerNumber = C.CustomerNumber

    Read the article

  • ActiveRecord + CodeIgniter - Return single value from query, not in array form.

    - by txmail
    Say you construct an activerecord query that will always just return a single value, how do you just address that single value instead of getting an array in return? For instance I am using an ActiveRecord query to return the SUM of a single column, it will only return this one single SUM, instead of having to parse the array is there a way to assign the value as a function return equal to that value instead of getting an array?

    Read the article

  • Porting Oracle Procedure to PostgreSQL

    - by Grasper
    I am porting an Oracle function into Postgres PGPLSQL.. I have been using this guide: http://www.postgresql.org/docs/8.1/static/plpgsql.html CREATE OR REPLACE PROCEDURE DATA_UPDATE (mission NUMBER, task NUMBER) AS BEGIN IF mission IS NOT NULL THEN UPDATE MISSION_OBJECTIVE MO SET (MO.MO_TKR_TOTAL_OFF_SCHEDULED, MO.MO_TKR_TOTAL_RECEIVERS) = (SELECT NVL(SUM(RR.TRQ_FUEL_OFFLOAD),0), NVL(SUM(RR.TRQ_NUMBER_RECEIVERS),0) FROM REFUELING_REQUEST RR, MISSION_REQUEST_PAIRING MRP WHERE MO.MSN_INT_ID = MRP.MSN_INT_ID AND MO.MO_INT_ID = MRP.MO_INT_ID AND MRP.REQ_INT_ID = RR.REQ_INT_ID) WHERE MO.MSN_INT_ID = mission AND MO.MO_INT_ID = task ; END IF ; COMMIT ; END ; I've got it this far: CREATE OR REPLACE FUNCTION DATA_UPDATE (NUMERIC, NUMERIC) RETURNS integer as ' DECLARE mission ALIAS for $1; task ALIAS for $2; BEGIN IF mission IS NOT NULL THEN UPDATE MISSION_OBJECTIVE MO SET (MO.MO_TKR_TOTAL_OFF_SCHEDULED, MO.MO_TKR_TOTAL_RECEIVERS) = (SELECT COALESCE(SUM(RR.TRQ_FUEL_OFFLOAD),0), COALESCE(SUM(RR.TRQ_NUMBER_RECEIVERS),0) FROM REFUELING_REQUEST RR, MISSION_REQUEST_PAIRING MRP WHERE MO.MSN_INT_ID = MRP.MSN_INT_ID AND MO.MO_INT_ID = MRP.MO_INT_ID AND MRP.REQ_INT_ID = RR.REQ_INT_ID) WHERE MO.MSN_INT_ID = mission AND MO.MO_INT_ID = task ; END IF; COMMIT; END; ' LANGUAGE plpgsql; This is the error I get: ERROR: syntax error at or near "SELECT" LINE 1: ...OTAL_OFF_SCHEDULED, MO.MO_TKR_TOTAL_RECEIVERS) = (SELECT COA... I do not know why this isn't working... any ideas?

    Read the article

  • How to use sum and count functions

    - by Odette
    hi guys I am trying to get the total count and total sum per salesperson but its not working in my WITH query Currently I have: WITH CALC1 AS (SELECT B.OTSMAN AS SALESMAN, COUNT(B.ONINUM) AS COUNT, SUM(B.OVSVAL) AS SVAL FROM @[email protected] AS B WHERE B.OCSGRP <> 'INT' AND B.OCSGRP <> 'INX' AND B.OCPSBR IN (@OCPSBR@) AND B.ICMATX <> '705' AND B.OCSGRP NOT LIKE 'S/%' GROUP BY B.OTSMAN, B.ONINUM ORDER BY B.OTSMAN ASC) SELECT SALESMAN, COUNT, SVAL FROM CALC1 ORDER BY SALESMAN THE RESULT IS: AM 1 79.03 AM 40 1337.70 AM 48 4627.15 AM 42 2727.40 AM 1 111.79 AM 1 1110.00 AM 52 3018.77 How do i change my query so I only get one record with the total count and value per salesperson? AM 1 13,011.84

    Read the article

  • Is possible to reuse subqueries?

    - by Gothmog
    Hello, I'm having some problems trying to perform a query. I have two tables, one with elements information, and another one with records related with the elements of the first table. The idea is to get in the same row the element information plus several records information. Structure could be explain like this: table [ id, name ] [1, '1'], [2, '2'] table2 [ id, type, value ] [1, 1, '2009-12-02'] [1, 2, '2010-01-03'] [1, 4, '2010-01-03'] [2, 1, '2010-01-02'] [2, 2, '2010-01-02'] [2, 2, '2010-01-03'] [2, 3, '2010-01-07'] [2, 4, '2010-01-07'] And this is want I would like to achieve: result [id, name, Column1, Column2, Column3, Column4] [1, '1', '2009-12-02', '2010-01-03', , '2010-01-03'] [2, '2', '2010-01-02', '2010-01-02', '2010-01-07', '2010-01-07'] The following query gets the proper result, but it seems to me extremely inefficient, having to iterate table2 for each column. Would be possible in anyway to do a subquery and reuse it? SELECT a.id, a.name, (select min(value) from table2 t where t.id = subquery.id and t.type = 1 group by t.type) as Column1, (select min(value) from table2 t where t.id = subquery.id and t.type = 2 group by t.type) as Column2, (select min(value) from table2 t where t.id = subquery.id and t.type = 3 group by t.type) as Column3, (select min(value) from table2 t where t.id = subquery.id and t.type = 4 group by t.type) as Column4 FROM (SELECT distinct id FROM table2 t WHERE (t.type in (1, 2, 3, 4)) AND t.value between '2010-01-01' and '2010-01-07') as subquery LEFT JOIN table a ON a.id = subquery.id

    Read the article

  • In MySQL, what is the most effective query design for joining large tables with many to many relatio

    - by lighthouse65
    In our application, we collect data on automotive engine performance -- basically source data on engine performance based on the engine type, the vehicle running it and the engine design. Currently, the basis for new row inserts is an engine on-off period; we monitor performance variables based on a change in engine state from active to inactive and vice versa. The related engineState table looks like this: +---------+-----------+---------------+---------------------+---------------------+-----------------+ | vehicle | engine | engine_state | state_start_time | state_end_time | engine_variable | +---------+-----------+---------------+---------------------+---------------------+-----------------+ | 080025 | E01 | active | 2008-01-24 16:19:15 | 2008-01-24 16:24:45 | 720 | | 080028 | E02 | inactive | 2008-01-24 16:19:25 | 2008-01-24 16:22:17 | 304 | +---------+-----------+---------------+---------------------+---------------------+-----------------+ For a specific analysis, we would like to analyze table content based on a row granularity of minutes, rather than the current basis of active / inactive engine state. For this, we are thinking of creating a simple productionMinute table with a row for each minute in the period we are analyzing and joining the productionMinute and engineEvent tables on the date-time columns in each table. So if our period of analysis is from 2009-12-01 to 2010-02-28, we would create a new table with 129,600 rows, one for each minute of each day for that three-month period. The first few rows of the productionMinute table: +---------------------+ | production_minute | +---------------------+ | 2009-12-01 00:00 | | 2009-12-01 00:01 | | 2009-12-01 00:02 | | 2009-12-01 00:03 | +---------------------+ The join between the tables would be engineState AS es LEFT JOIN productionMinute AS pm ON es.state_start_time <= pm.production_minute AND pm.production_minute <= es.event_end_time. This join, however, brings up multiple environmental issues: The engineState table has 5 million rows and the productionMinute table has 130,000 rows When an engineState row spans more than one minute (i.e. the difference between es.state_start_time and es.state_end_time is greater than one minute), as is the case in the example above, there are multiple productionMinute table rows that join to a single engineState table row When there is more than one engine in operation during any given minute, also as per the example above, multiple engineState table rows join to a single productionMinute row In testing our logic and using only a small table extract (one day rather than 3 months, for the productionMinute table) the query takes over an hour to generate. In researching this item in order to improve performance so that it would be feasible to query three months of data, our thoughts were to create a temporary table from the engineEvent one, eliminating any table data that is not critical for the analysis, and joining the temporary table to the productionMinute table. We are also planning on experimenting with different joins -- specifically an inner join -- to see if that would improve performance. What is the best query design for joining tables with the many:many relationship between the join predicates as outlined above? What is the best join type (left / right, inner)?

    Read the article

  • What is C# equivalent of PHP's mysql_fetch_array function?

    - by Mike Biff
    I am learning C#/ASP.NET and I am wondering what the C# equivalent of the following PHP code is? I know the userid, and I want to fetch the rows from this table into the array of the variable "row", so I then can use it as "row['name']" and "row['email']. $result = mysql_query("SELECT email, name FROM mytable WHERE id=7"); while ($row = mysql_fetch_array($result, MYSQL_ASSOC)) { printf("Email: %s Name: %s", $row["email"], $row["name"]); } Thanks.

    Read the article

  • How to dynamically choose two fields from a Linq query as a result

    - by Dr. Zim
    If you have a simple Linq query like: var result = from record in db.Customer select new { Text = record.Name, Value = record.ID.ToString() }; which is returning an object that can be mapped to a Drop Down List, is it possible to dynamically specify which fields map to Text and Value? Of course, you could do a big case (switch) statement, then code each Linq query separately but this isn't very elegant. What would be nice would be something like: (pseudo code) var myTextField = db.Customer["Name"]; // Could be an enumeration?? var myValueField = db.Customer["ID"]; // Idea: choose the field outside the query var result = from record in db.Customer select new { Text = myTextField, Value = myValueField };

    Read the article

  • Convert swf file to mp4 file using FFMPEG

    - by user1624004
    I now want to show an html5 video on a html page. Now I have an sample.swf file, I want to convert it to .mp4 or .ogg or .webm file. I have tried: ffmpeg -i sample.swf sample.mp4 But I got this error: [swf @ 0000000001feef40] Could not find codec parameters for stream 0 (Audio: pcm_s16le, 5512 Hz, 1 channels, 88 kb/s): unspecified sample format Consider increasing the value for the 'analyzeduration' and 'probesize' options [swf @ 0000000001feef40] Estimating duration from bitrate, this may be inaccurate Guessed Channel Layout for Input Stream #0.0 : mono Input #0, swf, from 'sample.swf': Duration: N/A, bitrate: N/A Stream #0:0: Audio: pcm_s16le, 5512 Hz, mono, 88 kb/s Stream #0:1: Video: mjpeg, yuvj444p, 1024x768 [SAR 100:100 DAR 4:3], 16 fps, 16 tbr, 16 tbn File 'sample.mp4' already exists. Overwrite ? [y/N] y Invalid sample format '(null)' Error opening filters!

    Read the article

  • Teradata group by time interval

    - by matt123
    Can anyonen help with Teradata? I want to create a query that is a standard select count(*) from Table where Column = Something but has a group by time period done by 5 minute time intervals the time column is in 'Time' format any idea?

    Read the article

  • Sorting NSSets of a core data entity - Objective-c

    - by ncohen
    Hi everyone, I would like to sort the data of a core data NSSet (I know we can do it only with arrays but let me explain...). I have an entity user who has a relationship to-many with the entity recipe. A recipe has the attributes name and id. I would like to get the data such that: Code: NSArray *id = [[user.recipes valueForKey:@"identity"] allObjects]; NSArray *name = [[user.recipes valueForKey:@"name"] allObjects]; if I take the object at index 1 in both arrays, they correspond to the same recipe... Thanks

    Read the article

  • How to check if a field is an Image field

    - by AJ
    Hello, This might seem an easy question for some, but I am struggling with it. I am trying to use SQLDataReader.GetFieldType to check if a certain field is an Image field. Lets assume the first field of the result set is an Image field, if I do: reader.GetFieldType(0).ToString; I get System.Byte[] But is this the correct way to check for it? I really don't like: if (reader.GetFieldType(0).ToString="System.Byte[]") Is there a better way? Thanks, AJ

    Read the article

  • Multiple rows with a single INSERT in SQLServer 2008

    - by Todd
    I am testing the speed of inserting multiple rows with a single INSERT statement. For example: INSERT INTO [MyTable] VALUES (5, 'dog'), (6, 'cat'), (3, 'fish) This is very fast until I pass 50 rows on a single statement, then the speed drops significantly. Inserting 10000 rows with batches of 50 take 0.9 seconds. Inserting 10000 rows with batches of 51 take 5.7 seconds. My question has two parts: Why is there such a hard performance drop at 50? Can I rely on this behavior and code my application to never send batches larger than 50? My tests were done in c++ and ADO.

    Read the article

  • How to ignore blank elements in linq query

    - by Maestro1024
    How to ignore blank elements in linq query I have a linq query var usersInDatabase = from user in licenseUserTable where user.FirstName == first_name && user.LastName == last_name select user; But if I get here and first_name or last_name is blank then I want to still evaluate the other data item.

    Read the article

  • Product Catalog Schema design

    - by FlySwat
    I'm building a proof of concept schema for a product catalog to possibly replace a very aging and crufty one we use. In our business, we sell both physical materials and services (one time and reoccurring charges). The current catalog schema has each distinct category broken out into individual tables, while this is nicely normalized and performs well, it is fairly difficult to extend. Adding a new attribute to a particular product involves changing the table schema and backpopulating old data. An idea I've been toying with has been something along the line of a base set of entity tables in 3rd normal form, these will contain the facts that are common among ALL products. Then, I'd like to build an Attribute-Entity-Value schema that allows each entity type to be extended in a flexible way using just data and no schema changes. Finally, I'd like to denormalize this data model into materialized views for each individual entity type. This views are what the application would access. We also have many tables that contain business rules and compatibility rules. These would join against the base entity tables instead of the views. My big concerns here are: Performance - Attribute-Entity-Value schemas are flexible, but typically perform poorly, should I be concerned? More Performance - Denormalizing using materialized views may have some risks, I'm not positive on this yet. Complexity - While this schema is flexible and maintainable using just data, I worry that the complexity of the design might make future schema changes difficult. For those who have designed product catalogs for large scale enterprises, am I going down the totally wrong path? Is there any good best practice schema design reading available for product catalogs?

    Read the article

  • Case-Insensitive String Comparison not working in C#?

    - by SB2055
    Based on the answer to this question: C# Case insensitive string compare I'm trying to do a case-insensitive comparison without using Compare or ToLower: var user = db.Users.FirstOrDefault(s => String.Equals(s.Username, username, StringComparison.OrdinalIgnoreCase)); However I get an error: Incorrect number of arguments supplied for call to method 'Boolean Equals(System.String, System.String, System.StringComparison)' What am I doing wrong?

    Read the article

  • Optimize this MySQL query?

    - by HipHop-opatamus
    The following query takes FOREVER to execute (30+ hrs on a Macbook w/4gig ram) - I'm looking for ways to make it run more efficiently. Any thoughts are appreciated! CREATE TABLE fc AS SELECT threadid, title, body, date, userlogin FROM f WHERE pid NOT IN (SELECT pid FROM ft) ORDER BY date; (table "f" is ~1 Gig / 1,843,000 row, table "ft" is 168mb, 216,000 rows) )

    Read the article

  • tsql getdate conversion

    - by Manjot
    Hi, I know that when i do the following, it converts getdate to int select cast (getdate() as int) Getdate output on my server is "2010-06-11 14:42:20.100" and the int to which the above command is converting to is 40339. What is this integer? Did this int consider minutes and seconds? i am confused. Please help. Regards Manjot

    Read the article

  • Best Practices - Stored Procedure Logging

    - by hgulyan
    If you have a long running SP, do you log somehow it's actions or just wait for this message? "Command(s) completed successfully." I assume, that there can be plenty solutions on this subject, but is there any best practice - a simple solution that is frequently used? EDIT I've found an interesting link on this subject http://weblogs.sqlteam.com/brettk/archive/2006/09/21/12391.aspx Article describes using a log table, but there's an issue The logging procedure must be executed outside of any transaction I can't call that insert outside, because of cursor that I use and insert a line to that table on every row. Any ideas?

    Read the article

< Previous Page | 836 837 838 839 840 841 842 843 844 845 846 847  | Next Page >