I have two identical tables that are located in two identical databases(with different name). I want to merge these two tables, but their primary keys are used in other tables, these tables look …
SQLQuery.list() returns the same entries
In my java code I have written like this. This query returning same records again and again. But in database I have only single record. String queryString = “select e.business_event_id, e.event_name …
DB2 add auto increment column to an existing table
I have a table with following schema in my DB2 database. CREATE TABLE IDN_OAUTH_CONSUMER_APPS ( CONSUMER_KEY VARCHAR (255) NOT NULL, CONSUMER_SECRET VARCHAR (512), USERNAME …
Filtering with Joins – Rails
I have two models Product and ProductProperties. So, I store the properties for products in the Product Properties model which is associated with another model Properties How can I implement a scope …
SELECT hex(name || age) AS X FROM Ages ORDER BY X
I am taking a Cousera course talking about SQL and there is one line of code I cannot understand. What does it mean by ‘hex(name || age)’? I know it turns the string into hexadecimal format using the …
Convert positive data into negetive data (entire column) in Postgres Server
The current data in my table is: a b ——— -1 5 -11 2 -5 32 My request is to convert every data of column a into negative value. But how to update the positive values into the …
JOIN (SELECT … ) ue ON 1=1?
I am reading an SQL query in Redshift and can’t understand the last part: … LEFT JOIN (SELECT MIN(modified) AS first_modified FROM user) ue ON 1=1 What does ON 1=1 mean here?
The specified schema name either does not exist or you do not have permission to use it
I am trying to create replica of my database from SQL server to another. For that I am generating script from original server and trying to run in another server. I’ve created database manually with …
How to select rows with uniq value of column and to calculate count?
I have table like this for example: I need to select each uniq column by ver and to calculate how much is total of rows by each uniq ver column I think each total to add into the new column …
Using EXCEPT clause in PostgreSQL
I am trying to use the EXCEPT clause to retrieve data from table. I want to get all the rows from table1 except the one’s that exist in table2. As far I understand, the following would not work: The only way I can use EXCEPT seems to be to select from the same tables or select columns that have the