I have two tables shown as above. I want to create a select statement that would have the following result: Basically, I want to join on ‘Model’ and ‘Num’ columns and bring ‘Val’ vales but break it …
Tag: database
Save other ID in database
I have 2 table here : 1. tblPurItem : itemID, categoryID, purchaseMeasurementID, stockMeasurementID, calculationMeasurementID, retailrecipeID 2. tblRecipe : recipeID, recipeName, …
Converting Queries into SQL Server syntax
I’ve been getting help from Chegg and most answers given to me don’t work for me. My first task is write a query where it list the employee assigned to the most projects. One response was: select …
SQLSTATE[HY093]: Invalid parameter number: number of bound variables does not match number of tokens – help needed
I’ve tried making a website which has a database connected to it and I’m getting the error message below SQLSTATE[HY093]: Invalid parameter number: number of bound variables does not match number of tokens This is my PHP code that I have written below Answer It took me a while to find, but I believe that PDO::prepare passes the named parameters
Simple SQL query returning null value
I just started studying SQL queries. I am practicing on this site: https://www.techonthenet.com/sql/joins_try_sql.php I want to find: “the name of the employee with the highest salary for every department”. My query is: And I get null value for first_name : I understand that the problem is due to the group by expressions. But how can I solve this? Tables: Answer
What is Internal process of below mentioned queries?
As per performance which query is optimistic query? Answer id | select_type | table | partitions | type | possible_keys | key | key_len | ref | rows | filtered | Extra -: | :———- | :—- | :——— | :—– | :———— | :—— | :—— | :——————————– | —: | ——-: | :———- 1 | SIMPLE | t1
How to compare a value within a range, inside (case when ~~ end as) query for mysql?
this is what I got: and I want to change this part as, for now I get the raw data of rssi, for example any digits between 0 and 120.. but now I want to change the rssi result if the data is in between certain range. For example, if rssi is between 0 and 20, its 1. if its
write an sql query to look up the names of classes that meets in room R128
Consider the following schema: Student(snum, sname, major,level) Class(cname, meets-at,room, fid) Faculty(fid, fname, depname) Enrolled(snum, cname) write an SQL query to find the names of all the classes that don’t meet in room R128 with the smallest number of students(compared to all other classes). Answer Try this
Mysql 8 How to use an if inside a stored procedure and using cte
I am using a CTE inside a stored procedure, and it works ok, but the problem is when I try to add a conditional, I got the following message: You have an error in your sql .. Syntax to use near ‘IF. Answer You cannot use an IF statement in a query. It is meant to execute a block of
What is the difference between count (*) and count(attribute_name)?
Is there any difference between COUNT(*) and COUNT(attribute_name)? I used count(attribute_name) as I thought that it would be specific hence the searching process would be easier. Is that true? It would be great to see any example with sql code with my issue to help me understand better Answer Imagine this table: count(column_name) also counts duplicate values. Consider: