sql-update

问题 i need to create a trigger that multiply two fields from two tables, but i have no idea of how to do it, so let's see if you can help me. Two tables, Products (product_name, price) Orders (product_name (foreign key),units_ordered) I need to add another field on table the Orders that multiply price from Products and units_ordered from Orders, so : total_price = price (from products) X units_ordered (from Orders) Thanks in advance, and sorry for my bad english. Regards 回答1: You don't need

问题 I am new to R and new to Stack Overflow, so apologies if I don't post this correctly! I have R linked to an Access database using the ODBC and DBI packages. I scoured the internet and couldn't find a way to write an update query, so I've created a loop that manually pretty much does the same thing. The problem is that to do this, I am using the dbSendStatement function. It seems that when you use that function you need a way to then end it before moving onto another query, or else you get

问题 Trying to update all elements of a nested array in a jsonb column, but only one element is updated. My query: update table_ set value_ = jsonb_set(value_,cte.json_path,cte.namevalue,false) FROM ( select vals2->'ao'->'sc'->'name' as namevalue, ('{iProps,'||index1-1||',value,rules,'||index2-1||',ao,sc}')::text[] as json_path from table_, jsonb_array_elements(value_->'iProps') with ordinality arr1(vals1,index1), jsonb_array_elements(vals1->'value'->'rules') with ordinality arr2(vals2,index2) )

问题 Im trying to update a value in one column based on a value in another table. I can do this if the columns are all in the same table like this: UPDATE wp_posts SET post_date = REPLACE (post_date, 'X', 'Y') WHERE meta_value = 'Z'; But I need to join two tables first before I can update: SELECT * FROM wp_posts LEFT OUTER JOIN wp_postmeta ON post_id = post_id How can I update based on the two tables I have joined? 回答1: Try this way, if you use SQL Server UPDATE WP SET WP.post_date = REPLACE(WPM

问题 I have a table in PostgreSQL that has an ID column that is supposed to be unique. However, a large number of the rows (around 3 million) currently have an ID of "1". What I know: The total number of rows The current maximum value for the ID column The number of rows with an (incorrect) ID of "1" What I need is a query that will pull all the rows with an ID of "1" and assign them a new ID that increments automatically so that every row in the table will have a unique ID. I'd like it to start

问题 I have a table in a Postgres 11.3 database with a jsonb column. Trying to update all objects inside a nested array name "iProps" . If the path {iProps -> value -> rules -> ao -> sc} is an object, then the path should be updated from an object to a string with the value {iProps -> value -> rules -> ao -> sc -> name} If the path {iProps -> value -> rules -> ao -> sc} is not present, then the object should be left unchanged. Test setup with query: Fiddle link Desired result: { "iProps": [ {

问题 Closed. This question does not meet Stack Overflow guidelines. It is not currently accepting answers. Want to improve this question? Update the question so it's on-topic for Stack Overflow. Closed 2 years ago . Improve this question Entity Framework can be very slow on mass insert/update/delete operations. Even the often suggested tweaks to turn off AutoDetectChanges and/or ValidateOnSaveEnabled does not always help. I have come across the Z.EntityFramework.Extensions on NuGet, but it seems

问题 Closed. This question does not meet Stack Overflow guidelines. It is not currently accepting answers. Want to improve this question? Update the question so it's on-topic for Stack Overflow. Closed 2 years ago . Improve this question Entity Framework can be very slow on mass insert/update/delete operations. Even the often suggested tweaks to turn off AutoDetectChanges and/or ValidateOnSaveEnabled does not always help. I have come across the Z.EntityFramework.Extensions on NuGet, but it seems

问题 Closed. This question does not meet Stack Overflow guidelines. It is not currently accepting answers. Want to improve this question? Update the question so it's on-topic for Stack Overflow. Closed 2 years ago . Improve this question Entity Framework can be very slow on mass insert/update/delete operations. Even the often suggested tweaks to turn off AutoDetectChanges and/or ValidateOnSaveEnabled does not always help. I have come across the Z.EntityFramework.Extensions on NuGet, but it seems

问题 item_id rate status --------- ----------- ------ 1 12 credit 2 10 credit 3 10 credit 4 20 cash 5 55 credit I have the above table, A user inputs and amount of 25. Now I want to update the status of the rows having credit as status from credit to cash until the sum of rate is 25, so in the above table the top 1 rows having a sum of 22 should get a status of cash. Since the user input is 25, I still have a balance of 3 (25-22), this balance should be deducted from the third row making the third