A core SQL statement, SELECT retrieves data from one or more tables or other sources of row set data such as views or table-valued functions.

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Select Between Date Range Mysql

I want to select records between 2 dates: select * from orders where orders.created <= '2015-07-31'; select * from orders where orders.created >= '2015-07-01' and orders.created <= '2015-...
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63 views

select group by with multiple AND conditions on the same columns

I've an sql table like this: SID|SERVICE_SID|ATTRIBUTE_SID|VALUE 1 2 5 "VAL1" 2 2 4 "VAL8" 3 2 3 "VAL4" 4 11 5 ...
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Oracle: guaranteeing unmodified database state with queries?

If the first word of a SQL statement is either WITH or SELECT, is the statement guaranteed not to change the state of the database? i.e. is this loop "safe"? read SQL string if string begins with ...
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How to improve the performance of this select query?

I have two tables: TABLE1 and TABLE2. And I am running this select query to fetch the data. It takes long time to run: SELECT TABLE1.* , TABLE2.COL1 , TABLE2.COL4 FROM TABLE1, TABLE2 WHERE ...
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How to select only first column dynamically on mysql

I have to select only first column. Because of i dont want to select all columns like SELECT * FROM table. But my first columns may vary like following: id article_id user_id product_id page_id etc.. ...
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Altering strings while selecting them

I'm working in SQL Server 2008, I have a varchar(255) column in my table, I want to select out all of the strings which contain the ':' character, and select the first part of the string before (but ...
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12k views

Delete from table where multiple fields match select subquery from other table

I want to delete an entry in a table where multiple fields match the results of another select subquery which takes data from another table. This is what I have so far, though it doesn't work: ...
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46 views

Order by on an alphanumerical column

I have a column that has strings of the following type: Miller 10 Allen 20 King 10 .... Jones 100 I try to sort the column based on the numerical part of the data. I tried the following: SELECT *...
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Need a way to query a table, and JOIN it with the TOP 1 related record from an other table

As a follow up to this question, I'm wondering if there is a better and/or more efficient way to gather the data in question. As stated, this query does return me 95% of the data I need -- SELECT dv....
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Why this query returns rows that I don't want to be there

I'm trying to running this query: SELECT * FROM (`default_users`) LEFT JOIN `default_profiles` ON `default_profiles`.`user_id` = `default_users`.`id` WHERE `default_users`.`group_id` ...
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44 views

Is there a way to find the partition or subpartition name where my ID belongs

I know if I need to select from any partition I need to provide partition name SELECT * FROM TABLE PARTITION(P1); What if I need to know which partition a particular value belongs using a sql query ...
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Counting rows from a subquery

Simple: I would like to count the number of rows from the sub-query. Note that status is whether the host is online or not. Bad code SELECT COUNT(ip_address) FROM `ports` ( SELECT DISTINCT ...
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How to select distinct record?

I have a table, as follows: ID | Name | MyID 1 | Alan | 2 2 | Alan | 2 3 | John | 3 I want to select the records as follows: If two records have the duplicate ...
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55 views

Multiple left join where not in another table

I have the following tables (there is more detailed data in each one, I just put the minimum to create a sample): __________ _____________ _____________ _____________ | person | | provider | | ...
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71 views

How to select users that doesn't in the role

I have 4 roles which are Admin, Procurement, Accounting, HR roles and 3 tables which are Users, Roles and Userroles. They user can have many roles as well as the roles can have many users. the problem ...
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407 views

REPLACE INTO SELECT from table

Is there a way in DB2 to replace the entire table with just selected rows from the same table ? Something like REPLACE into tableName select * from tableName where col1='a'; (I can export the ...
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531 views

How to find all schemas where a table has records?

In my Oracle database, I have a number of schemas (users/owners) with similar table structures (about 100 in total). However, some tables are empty in a lot of schemas. Is there a way to find out for ...
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193 views

Need help in incrementing the date in oracle

Error thrown as "Invalid number" while trying to increment the date. Given below is the query executed through sqlplus. Please help me on this. select ''''||to_date(:To_date, 'dd-mon-yyyy')+1||'''' ...
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Unexpected empty result [closed]

select a,b from table1 where a not in (select x as a from table2) AND b not in (select y as b from table3) The above query gives an empty result. Why? And how should I construct this combined ...
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joins with “could be blank” conditions

Question is most probably stupid but I am stuck on this and cant think anymore(Pissed Off). I have these tables-> employee(has a column foreign to location),location and location_flag. And I need ...
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2k views

Group by age range and gender with aggregation function on some columns

In Mysql, I have a patient table with id, birth_year and gender. Next table is transactions in which I have id, patient_id [FK from patient] and checkup_date. I need to select rows such that I get ...
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563 views

Multiple SELECT vs single SELECT over TCIP

My question is a performance one: I need to select roughly 400+ rows, i know their ids. currently i loop in code and fire off multiple queries over tcp/ip - because its easy: ... select [columns] ...
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329 views

How to calculate average of list of qualifications of each pupil MYSQL

I have this database and query: http://sqlfiddle.com/#!2/b4cf72/116 And I would like to add a column with the average of the exam qualifications. However, I try doing this but it tells me there are ...
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332 views

Need to optimize simple SELECT query for InnoDB table with 2million rows

I'd like to make this query the fastest possible, since it's called really often. SELECT login_events.id FROM login_events WHERE ( DATE(created_at) >= DATE(CURRENT_DATE) AND person_id = 1 ) ...
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10k views

Select records in one table but not in another, when the second table is not matching on primary key

I have two tables from which I need only the results that appear in one table (list) which do not appear in the second table (cardinal). The list table's primary key is sku, and the table has a ...
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2k views

Insert from one row to another using cases

My original table was(being used since 2005): CREATE TABLE `request` ( `msg` VARCHAR(150) NOT NULL, `id` VARCHAR(20) NOT NULL, `ctg` VARCHAR(10) NOT NULL DEFAULT 'misc', `date` ...
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271 views

MySQL SELECT query: i want show duplicated entries

Example My query is: SELECT code_CAT FROM categories WHERE id_code IN(14,14,14,14); output is: 53724 Only one row. Instead I want this output: 53724 53724 53724 53724 How can I achieve this?...
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1k views

How to change the display of an empty string in mysql command line tool?

I'm maintaining a database with InnoDB tables. These tables have some columns of type (from show create table): `val0` varchar(30) default NULL, `val1` varchar(30) default NULL, etc... From the ...
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5k views

How can I select the latest record having one state where no later records exist with any other state?

I want to select the last record (by datetime) having a given state where no later records exist with any other state for each given "widget". widget state timestamp ------ ----- -------...
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174 views

Complex mysql selection

I have the following table, id | booki_id | bet_id | bet | bettype | line | odds 1 | 123 | 321 | 1 | 3way | 0,0 | 2.3 2 | 123 | 321 | 2 | 3way | ...
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59 views

SQL Server query problem when selecting data from child table based on column in parent table

I am using MS SQL Server 2008 using Management Studio. I am running a query(below) to extract dates and value based on the 'ticker' column from the parent table, the attribute column (child) , and ...
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32 views

ORACLE: Changing the grouping of a data to be based on month breakdowns

To keep this short and to the point, I am looking at modifying the grouping for this SQL query to go from NAME to Month/yy Here is a example of the script, and screenshots of the output file This is ...
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31 views

Get previous and next row from result set help

I have to get "relevant" results from a table by joining it on another table and filtering the results on parent id and current id, this all goes fine until your current id is either the first or the ...
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60 views

MySQL INSERT … SELECT Performance

I know that this query will lock table2: UPDATE table1... SELECT .. FROM table2 How about this query ? INSERT INTO table1... SELECT .. FROM table2 Does this query also create a lock on table2?
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Error 1052 Field is Ambiguous using Inner Join Function

Error '1052' Field is ambiguous. I understand the error that is happening, and I've looked at several places for the fix and then applied the inner join function in attempt to fix it. It's still not ...
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1answer
189 views

Vertica performance on select from view with union

We have a huge number of rows(tens of millions), and for each table we have an associated view that is a select with UNION ALL between that table and several others. Now, we are doing a select from ...
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SELECT with equal chance between same IDs - MySQL

How can I SELECT data with equal chances for same IDs in MySQL (for php). For example, assume below data structure: id value 1 alfa 1 beta 1 gamma 2 hello 2 bye 3 sky I want (...
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65 views

Unknown column 'actions_in_group' in 'field list'

I keep getting: Unknown column 'actions_in_group' in 'field list' Here's the SQLFiddle: http://sqlfiddle.com/#!9/4ddf0/19 SELECT *, SUM(actions_in_group) AS total_rows_in_group, GROUP_CONCAT(...
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59 views

Recommended Database(s) for Selecting Random Rows

I'm familiar with selecting random rows from a table in PostgreSQL. It's really slow. I've looked into some other databases and they all seem to be bad at it. Mostly because it's not a normal use case ...
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Select data where column value exists in seperate rows for same reference id

This is on a MySQL database. Locations have services. What I want is to get all results where service_id is 2 AND 3, not OR so using IN is out I believe. Database ---------------------------- | ...
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MSSQL Select all parent rows for which exists a combination of children rows with desired value

I would like to select all parent rows for which exists a combination of children rows with desired value. The easiest approach is to use multiple exists clauses, but this is not optimal - anyone ...
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323 views

Can I parse a text value from a specific column in a query (MySQL)?

I was playing around with Sakila and I ran across the actor_info view and one of its columns is film_info which is a detail of all the movies one actor has worked in. For example a query would be: ...
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5k views

MySQL Count rows from another table for each record in table

SELECT student.StudentID, student.`Name`, COUNT(attendance.AttendanceID) AS Total FROM student LEFT JOIN attendance ON student.StudentID = attendance.StudentID I am trying to count the last ...
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376 views

How to make a single row result query to return multiple rows

I have the following WITH SQL Query which does select a set of filling stations along a route within the distance of 1000m. To have the measurement in meter I cast the geometries to geography. I also ...
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1answer
54 views

Creating a View with results from join of scalar tables

I am really bad at SQL Queries and seem to be stuck at a very odd problem. Maybe there's an alternative of doing this, but I simply can't figure it out. Maybe you guys can help! So, here's my ...
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2k views

Select only rows with minimum values from union table

SQL Server 2005 Here is a sampling of the data from a union of two tables (named "vProducts_All"): DBID UPC Price1 Price2 1 023614025559 689.0000 649.0000 2 ...
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556 views

Select statement for selecting every week's log record

Here is a simplified version of the table in question: +------------------------------------------------------+ | DatabaseName | LogRecordNumber | LogTimestamp | +------------------------------...
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512 views

Determine last time a mysql table was accessed (i.e. SELECT'ed)

In my mysql DB schema there are old tables that are no longer used. I want to come up with a systematic way to show my developer a list of tables and last time they were read (SELECT'ed, not UPDATE'ed:...
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Should I drop this column or is there a query that can achieve a results table without duplicate columns?

I use a column named active in several of my database tables to adjust whether a particular entry/row/user/etc should be included in future query result tables instead of deleting the information. ...
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250 views

MySQL select with left join query

I have following code. select class.name as classname, class.hours as hours, teachers.first_name as teacherFirstName, teachers.last_name as teacherLastName from teachers,class left join ...