I am working on a Store Procedure where I need to update records from from table 1 into table 2.
Table1: contains the following 4 columns
----------------------------------------------
| ID | TableName | ColumnName | Value |
----------------------------------------------
| 1 | [UserDetails] | [FinalScore] | 92 |
| 2 | [UserDetails] | [FinalScore] | 89 |
| 3 | [UserDetails] | [FinalScore] | 65 |
| 4 | [UserDetails] | [FinalScore] | 91 |
| 5 | [UserDetails] | [FinalScore] | 76 |
| 1 |[EmployeeDetail]| [ScoreData] | 0.91 |
----------------------------------------------
UserDetails table
-----------------------------------------------------------
| UserID | UserName | ContactNo | FinalScore |
-----------------------------------------------------------
| 1 | John G | +13288992342 | 0 |
| 2 | Leonard J | +14581232342 | 0 |
| 3 | Max R | +17123992342 | 0 |
| 4 | Robert H | +15688992122 | 0 |
| 5 | Jimmy L | +1328996782 | 0 |
-----------------------------------------------------------
Need to load all the data from table1 into the corresponding destination table for large amount of data (30,000 to 60,000) records.
Table1 contains the ID (from ID Column in table1) and FinalScore (from ColumnName Column in table1) in the destination table (from TableName Column in table1) where the value (from Value Column in table1) needs to be loaded.
End Result of UserDetails table after SP execution :
-----------------------------------------------------------
| UserID | UserName | ContactNo | FinalScore |
-----------------------------------------------------------
| 1 | John G | +13288992342 | 92 |
| 2 | Leonard J | +14581232342 | 89 |
| 3 | Max R | +17123992342 | 65 |
| 4 | Robert H | +15688992122 | 91 |
| 5 | Jimmy L | +1328996782 | 76 |
-----------------------------------------------------------
I am not sure how to load the data from "table1" into destination table (userdetails table) for bulk data as update query in a loop is taking very long time to complete.
It's not pivot what you're after but a simple join:
select
a.userid, a.contactno, b.finalscore
from UserDetails a
join table1 b on a.id = b.id
alternatively, if you want to update the old table without creating a new one, you can update join
SQL update query using joins
Related
this query takes 24 seconds and returns 1891 results:
SELECT p.STATE, p.REFNUM, p.CODE, p.TYPE, i.STATE, pj.NAME, pj.DOCUMENT
TABLE p
inner join TABLE2 i on i.REFNUM = p.REFNUM
inner join TABLE3 pj on pj.NUMBER = i.NUMBER and p.OFIC_ID = pj.OFIC_ID and p.PUB_ID = pj.PUB_ID
inner join OFICE o on t.OFIC_ID = p.OFIC_ID and o.PUB_ID = p.PUB_ID
inner join GROUP glad on glad.GROUP_CODE=p.GROUP_CODE
WHERE glad.GROUP_TYPE ='3' AND i.STATE = '1'
AND p.PUB_ID IN ('05','11','12','09','08','13','04','02','01','06','10','03','07','14')
AND pj.NAME LIKE 'BANK%'
ORDER BY o.NAME,p.ID;
I have these indexes:
CREATE INDEX IND_TABLE1_REFNUM_ZONE ON TABLE1 (PUB_ID, OFIC_ID, REFNUM, ZONE_ID)
CREATE INDEX IND_TABLE1_REFNUMPUB ON TABLE1 (REFNUM, PUB_ID, OFIC_ID, GROUP_CODE );
CREATE INDEX IND_TABLE1_GROUP ON TABLE1 (PUB_ID, GROUP_CODE, REFNUM, OFIC_ID)
CREATE INDEX IND_TABLE2_REF ON TABLE2 (REFNUM, NUMBER, STATE);
CREATE INDEX IND_TABLE2_QUERY ON TABLE2 (NUMBER, TYPE, STATE, REFNUM, NUM, CODE);
CREATE INDEX IND_TABLE2_REFNUM ON TABLE2 (REFNUM)
CREATE INDEX IND_TABLE2_NUMBER ON TABLE2 (NUMBER)
CREATE INDEX IND_TABLE3_NUM ON TABLE3 (NUMBER, PUB_ID, OFIC_ID, NAME );
CREATE INDEX IND_TABLE3_NAME ON TABLE3 ( NAME );
CREATE INDEX IND_GROUP_COD ON GROUP (GROUP_CODE, GROUP_TYPE)
I made the following queries to see how many records are in each table:
SELECT count(*) FROM TABLE1 --> 18298458 results
SELECT count(*) FROM TABLE2 --> 60627924 results
SELECT count(*) FROM TABLE3 --> 18425913 results
SELECT count(*) FROM OFICE --> 65 results
SELECT count(*) FROM TABLE1 p INNER JOIN GROUP glad on glad.GROUP_CODE=p.GROUP_CODE where glad.GROUP_TYPE ='3' AND p.PUB_ID IN ('05','11','12','09','08','13','04','02','01','06','10','03','07','14') --> 1314077 results
SELECT count(*) FROM TABLE1 p INNER JOIN GROUP glad on glad.GROUP_CODE=p.GROUP_CODE where glad.GROUP_TYPE ='3' AND p.PUB_ID IN ('05') --> 53754 results
SELECT count(*) FROM TABLE3 WHERE NAME LIKE 'BANK%' --> 1922081 results
this is the plan generated by oracle:
-----------------------------------------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost | Pstart| Pstop |
-----------------------------------------------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 291K| 38M| 384K| | |
| 1 | SORT ORDER BY | | 291K| 38M| 384K| | |
| 2 | HASH JOIN | | 291K| 38M| 375K| | |
| 3 | TABLE ACCESS FULL | OFICE | 64 | 960 | 3 | | |
| 4 | HASH JOIN | | 291K| 34M| 375K| | |
| 5 | INDEX SKIP SCAN | IND_GROUP_COD | 47 | 329 | 1 | | |
| 6 | HASH JOIN | | 452K| 50M| 375K| | |
| 7 | PART JOIN FILTER CREATE | :BF0000 | 452K| 50M| 375K| | |
| 8 | NESTED LOOPS | | 452K| 50M| 375K| | |
| 9 | NESTED LOOPS | | | | | | |
| 10 | STATISTICS COLLECTOR | | | | | | |
| 11 | HASH JOIN | | 2100K| 166M| 252K| | |
| 12 | NESTED LOOPS | | 2100K| 166M| 252K| | |
| 13 | STATISTICS COLLECTOR | | | | | | |
| 14 | PARTITION RANGE ALL | | 1681K| 89M| 82582 | 1 | 19 |
| 15 | PARTITION HASH ALL | | 1681K| 89M| 82582 | 1 | 32 |
| 16 | TABLE ACCESS FULL | TABLE3 | 1681K| 89M| 82582 | 1 | 608 |
| 17 | INDEX RANGE SCAN | IND_TABLE2_QUERY | 1 | 27 | 103K| | |
| 18 | INDEX FAST FULL SCAN | IND_TABLE2_QUERY | 32M| 845M| 103K| | |
| 19 | INDEX RANGE SCAN | IND_TABLE1_REFNUM_ZONE| | | | | |
| 20 | TABLE ACCESS BY GLOBAL INDEX ROWID| TABLE1 | 1 | 35 | 70380 | ROWID | ROWID |
| 21 | PARTITION RANGE ALL | | 19M| 650M| 70380 | 1 | 19 |
| 22 | PARTITION HASH JOIN-FILTER | | 19M| 650M| 70380 |:BF0000|:BF0000|
| 23 | TABLE ACCESS FULL | TABLE1 | 19M| 650M| 70380 | 1 | 608 |
-----------------------------------------------------------------------------------------------------------------
I think it takes time because this one is using TABLE ACCESS FULL for TABLE1 and TABLE3
if I perform the query filtering only PUB_ID='05' instead of all the numbers in the above query, the query returns 181 results and takes 8 seconds and in that case oracle generates this plan:
--------------------------------------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost | Pstart| Pstop |
--------------------------------------------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 797 | 108K| 312K| | |
| 1 | SORT ORDER BY | | 797 | 108K| 312K| | |
| 2 | NESTED LOOPS | | 797 | 108K| 312K| | |
| 3 | HASH JOIN | | 1238 | 160K| 312K| | |
| 4 | TABLE ACCESS BY INDEX ROWID BATCHED| OFICE | 3 | 45 | 2 | | |
| 5 | INDEX RANGE SCAN | SYS_C0034405 | 3 | | 1 | | |
| 6 | HASH JOIN | | 2091 | 240K| 312K| | |
| 7 | PART JOIN FILTER CREATE | :BF0000 | 66316 | 5375K| 241K| | |
| 8 | NESTED LOOPS | | 66316 | 5375K| 241K| | |
| 9 | PARTITION RANGE ALL | | 53085 | 2903K| 82490 | 1 | 19 |
| 10 | PARTITION HASH ALL | | 53085 | 2903K| 82490 | 1 | 32 |
| 11 | TABLE ACCESS FULL | TABLE3 | 53085 | 2903K| 82490 | 1 | 608 |
| 12 | INDEX RANGE SCAN | IND_TABLE2_QUERY | 1 | 27 | 3 | | |
| 13 | PARTITION RANGE ALL | | 762K| 25M| 68657 | 1 | 19 |
| 14 | PARTITION HASH JOIN-FILTER | | 762K| 25M| 68657 |:BF0000|:BF0000|
| 15 | TABLE ACCESS FULL | TABLE1 | 762K| 25M| 68657 | 1 | 608 |
| 16 | INDEX RANGE SCAN | IND_GROUP_COD | 1 | 7 | 0 | | |
--------------------------------------------------------------------------------------------------------------
SYS_C0034405 is the primary key of OFFICE which contains these fields: (PUB_ID, REG_ID)
if in addition to filtering only PUB_ID='05' I remove the "order by", the query takes only 3.5 seconds but I definitely have to return the ordered data and I would prefer to be able to filter several PUB_IDs
I thought the query could be improved if I removed the "inner join" from GROUP and changed the filter "glad.GROUP_TYPE ='3'" to "p.GROUP_CODE in ('01','07','10','21 ')" (these are all type 3 codes), because now it should use the IND_TABLE1_GROUP index but instead of improving, it gets worse, it takes 13 seconds even filtering only PUB_ID='05'; This is the plan that oracle generates:
------------------------------------------------------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost | Pstart| Pstop |
------------------------------------------------------------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 47 | 6251 | 172K| | |
| 1 | SORT ORDER BY | | 47 | 6251 | 172K| | |
| 2 | HASH JOIN | | 47 | 6251 | 172K| | |
| 3 | PARTITION RANGE ALL | | 47786 | 2613K| 82490 | 1 | 19 |
| 4 | PARTITION HASH ALL | | 47786 | 2613K| 82490 | 1 | 32 |
| 5 | TABLE ACCESS FULL | TABLE3 | 47786 | 2613K| 82490 | 1 | 608 |
| 6 | HASH JOIN | | 41945 | 3154K| 89633 | | |
| 7 | NESTED LOOPS | | 41945 | 3154K| 89633 | | |
| 8 | NESTED LOOPS | | 75740 | 3154K| 89633 | | |
| 9 | STATISTICS COLLECTOR | | | | | | |
| 10 | NESTED LOOPS | | 18935 | 924K| 15985 | | |
| 11 | TABLE ACCESS BY INDEX ROWID BATCHED | OFICE | 3 | 45 | 2 | | |
| 12 | INDEX RANGE SCAN | SYS_C0034405 | 3 | | 1 | | |
| 13 | INLIST ITERATOR | | | | | | |
| 14 | TABLE ACCESS BY GLOBAL INDEX ROWID BATCHED| TABLE1 | 6312 | 215K| 7039 | ROWID | ROWID |
| 15 | INDEX RANGE SCAN | IND_TABLE1_GROUP | 6828 | | 284 | | |
| 16 | INDEX RANGE SCAN | IND_TABLE2_REFNUM | 4 | | 2 | | |
| 17 | TABLE ACCESS BY INDEX ROWID | TABLE2 | 2 | 54 | 4 | | |
| 18 | INDEX FAST FULL SCAN | IND_TABLE2_QUERY | 2 | 54 | 2 | | |
------------------------------------------------------------------------------------------------------------------------------
And if I put all the PUB_IDs, Oracle generates this plan (it doesn't even use the IND_TABLE1_GROUP index anymore):
-------------------------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost | Pstart| Pstop |
-------------------------------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 35661 | 4631K| 345K| | |
| 1 | SORT ORDER BY | | 35661 | 4631K| 345K| | |
| 2 | HASH JOIN | | 35661 | 4631K| 344K| | |
| 3 | TABLE ACCESS FULL | OFICE | 64 | 960 | 3 | | |
| 4 | HASH JOIN | | 35661 | 4109K| 344K| | |
| 5 | PARTITION RANGE ALL | | 1360K| 45M| 79580 | 1 | 19 |
| 6 | PARTITION HASH ALL | | 1360K| 45M| 79580 | 1 | 32 |
| 7 | TABLE ACCESS FULL | TABLE1 | 1360K| 45M| 79580 | 1 | 608 |
| 8 | HASH JOIN | | 2100K| 166M| 252K| | |
| 9 | NESTED LOOPS | | 2100K| 166M| 252K| | |
| 10 | STATISTICS COLLECTOR | | | | | | |
| 11 | PARTITION RANGE ALL | | 1681K| 89M| 82582 | 1 | 19 |
| 12 | PARTITION HASH ALL | | 1681K| 89M| 82582 | 1 | 32 |
| 13 | TABLE ACCESS FULL | TABLE3 | 1681K| 89M| 82582 | 1 | 608 |
| 14 | INDEX RANGE SCAN | IND_TABLE2_QUERY | 1 | 27 | 103K| | |
| 15 | INDEX FAST FULL SCAN | IND_TABLE2_QUERY | 32M| 845M| 103K| | |
-------------------------------------------------------------------------------------------------
I have 2 tables, with the same exact fields and fields names. i am trying to inner join them but im having some difficulty determining how i can get my results in my desired format.
I know i can do select a.customer, a.id, a.date, a.line, a.product, b.customer, b.id, b.date, b.line, b.product but instead of having my A data and B data on the same row, id like for them to be on seperate rows.
I have 2 tables, with the same exact fields and fields names, i am trying to inner join them so that unique line becomes a row.
Table A:
|customer| id | Date | line | Product|
|--------|-----|---------|------|--------|
| 445678 | 123 | 1/1/22 | 10 | 88975 |
| 853652 | 456 | 1/10/22 | 5 | 55876 |
| 845689 | 789 | 1/25/22 | 1 | 45587 |
TABLE B:
|customer| id | Date | line | Product|
|--------|-----|---------|------|--------|
| 445678 | 489 | 1/1/22 | 1 | 87574 |
| 853652 | 853 | 1/10/22 | 12 | 45678 |
| 587435 | 157 | 2/12/22 | 3 | 25896 |
DESIRED RESULTS:
|customer| id | Date | line | Product|
|--------|-----|---------|------|--------|
| 445678 | 123 | 1/1/22 | 10 | 88975 |
| 445678 | 489 | 1/1/22 | 1 | 87574 |
| 853652 | 456 | 1/10/22 | 5 | 55876 |
| 853652 | 853 | 1/10/22 | 12 | 45678 |
my query:
select a.customer, a.id, a.date, a.line, a.product
from data1 a
inner join data2 b
on a.date = b.date
and a.customer = b.customer
I have two tables:
ProjectProduct (two IDs for project and product) and
ProductStatus (which contains quality ratings for products).
Table: ProjectProduct
| productID | projectID |
| --------- | --------- |
| 39 | 26 |
| 40 | 26 |
| 41 | 26 |
| 42 | 26 |
Table: ProductStatus
| id | projectID | productID | typeID | Status | Comment | RatedBy |
| --- | --------- | --------- | ------ | ------ | ------------ | ------- |
| 1 | 26 | 39 | 2 | 30 | comm1 | 0 |
| 2 | 26 | 39 | 2 | 70 | comm2 | 0 |
| 22 | 26 | 39 | 1 | 70 | diff type | 0 |
| 3 | 26 | 39 | 2 | 100 | comm3 | 0 |
| 4 | 26 | 39 | 2 | 70 | diff ratedBy | 1 |
| 5 | 26 | 39 | 2 | 100 | comm5 | 0 |
| 6 | 26 | 39 | 2 | 30 | comm6 | 0 |
I need to join those two tables so that every product in the ProjectProduct table will display a Status value even if there is no corosponding entry in the ProductStatus table.
In above example only productID 39 exists in both tables. To show all productIDs the output should contain a zero value in the Status column for productIDs 40 to 42.
This is the part that I cannot figure out. For example the ProductStatus TypeID can contain 1 or 2. TypeID 2 has to be distinguished between RatedBy which can contain 0 or 1. Do I need the table or select statement to reflect all possible permutations?
Also only the row with the highest ID grouped by projectID, productID, typeID, RatedBy should be picked where there is an existing rating.
Desired output:
I also created a SQL Fiddle
I hope you can guide me in the right direction.
Thank you.
Query
SELECT ProjectProduct.projectID, ProjectProduct.productID, ProductStatus.typeid,ProductStatus.status,ProductStatus.Comment,ProductStatus.ratedBY
FROM ProjectProduct
left join
(
SELECT max(ID) id, productID,projectID
FROM ProductStatus
where typeID = 2
and ratedBY = 0
group BY productID,projectID ) maxproduct on ProjectProduct.productID = maxproduct.productID and ProjectProduct.projectID = maxproduct.projectID
left join ProductStatus on ProductStatus.id = maxproduct.ID
Output
you can use temp table like that:
select Max(Id) maxID ,ProductId,ProjectId into #Temp1 from ProductStatus
where typeID=2 and RatedBy=0
group by ProductId,ProjectId
select * into #Temp2 from ProductStatus where Id In (select MaxId from #Temp1)
select p.ProjectId,p.ProductId, 2 as typeID,isnull(t.status,0) as Status,t.Comment,0 as RatedBy
from ProjectProduct p left join #Temp2 t on p.ProductId=t.ProductId and p.ProjectId=t.ProjectId
I have three tables:
My products with their IDs and their features.
is a table with treatments of my products with a treatment-ID, a method, and a date. The treatments are done in batches of many products so there is a crosstable
with the products IDs and the treatment IDs and a bool value for the success of the treatment.
Each product can undergo many different treatments so there is a many-to-many relation. I now want to add to the product table (1.) for every product a value that shows the method of its most recent successful treatment if there is any.
I made a query that groups the crosstable's entries by product-ID but I don't know how to show the method and date of it's last treatment.
table 1:
| productID | size | weight | height | ... |
|-----------|:----:|-------:|--------|-----|
| 1 | 13 | 16 | 9 | ... |
| 2 | 12 | 17 | 12 | ... |
| 3 | 11 | 15 | 15 | ... |
| ... | ... | ... | ... | ... |
table 2:
| treatmentID | method | date |
|-------------|:--------:|-----------:|
| 1 | dye blue | 01.02.2016 |
| 2 | dye red | 01.02.2017 |
| 3 | dye blue | 01.02.2018 |
| ... | ... | ... |
table 3:
| productID | treatmentID | success |
|-----------|:-----------:|--------:|
| 1 | 1 | yes |
| 1 | 2 | yes |
| 1 | 3 | no |
| ... | ... | ... |
I need table 1 to be like:
table 1:
| productID | size | weight | height | latest succesful method |
|-----------|:----:|-------:|--------|-------------------------|
| 1 | 13 | 16 | 9 | dye red |
| 2 | 12 | 17 | 12 | ... |
| 3 | 11 | 15 | 15 | ... |
| ... | ... | ... | ... | ... |
My query:
SELECT table3.productID, table2.method
FROM table2 INNER JOIN table3 ON table2.treatmentID = table3.treatmentID
GROUP BY table3.productID, table2.method
HAVING (((table3.productID)=Max([table2].[date])))
ORDER BY table3.productID DESC;
but this does NOT show only one (the most recent) entry but all of them.
Simplest solution here would be to write either a subquery within your sql, or create a new query to act as a subquery(it will look like a table) to help indicate(or elminate) the records you want to see.
Using similar but potentially slightly different source data as you only gave one example.
Table1
| ProductID | Size | Weight | Height |
|-----------|------|--------|--------|
| 1 | 13 | 16 | 9 |
| 2 | 12 | 17 | 12 |
| 3 | 11 | 15 | 15 |
Table2
| TreatmentID | Method | Date |
|-------------|------------|----------|
| 1 | dye blue | 1/2/2016 |
| 2 | dye red | 1/2/2017 |
| 3 | dye blue | 1/2/2018 |
| 4 | dye yellow | 1/4/2017 |
| 5 | dye brown | 1/5/2018 |
Table3
| ProductID | TreatmentID | Success |
|-----------|-------------|---------|
| 1 | 1 | yes |
| 1 | 2 | yes |
| 1 | 3 | no |
| 2 | 4 | no |
| 2 | 5 | yes |
First order of business is to get the max(dates) and productIds of successful treatments.
We'll do this by aggregating the date along with the productIDs and "success".
SELECT Table3.productid, Max(Table2.Date) AS MaxOfdate, Table3.success
FROM Table2 INNER JOIN Table3 ON Table2.treatmentid = Table3.treatmentid
GROUP BY Table3.productid, Table3.success;
This should give us something along the lines of:
| ProductID | MaxofDate | Success |
|-----------|-----------|---------|
| 1 | 1/2/2018 | No |
| 1 | 1/2/2017 | Yes |
| 2 | 1/4/2017 | No |
| 2 | 1/8/2017 | Yes |
We'll save this query as a "regular" query. I named mine "max", you should probably use something more descriptive. You'll see "max" in this next query.
Next we'll join tables1-3 together but in addition we will also use this "max" subquery to link tables 1 and 2 by the productID and MaxOfDate to TreatmentDate where success = "yes" to find the details of the most recent SUCCESSFUL treatment.
SELECT table1.productid, table1.size, table1.weight, table1.height, Table2.method
FROM ((table1 INNER JOIN [max] ON table1.productid = max.productid)
INNER JOIN Table2 ON max.MaxOfdate = Table2.date) INNER JOIN Table3 ON
(Table2.treatmentid = Table3.treatmentid) AND (table1.productid = Table3.productid)
WHERE (((max.success)="yes"));
The design will look something like this:
Design
(ps. you can add queries to your design query editor by clicking on the "Queries" tab when you are adding tables to your query design. They act just like tables, just be careful as very detailed queries tend to bog down Access)
Running this query should give us our final results.
| ProductID | Size | Weight | Height | Method |
|-----------|------|--------|--------|-----------|
| 1 | 13 | 16 | 9 | dye red |
| 2 | 12 | 17 | 12 | dye brown |
I made a INNER JOIN in stored procedure, but I don't know what to put to my WHERE clause to filter those column with null values and only shows those rows who has not null on a particular column.
CREATE PROCEDURE [dbo].[25]
#param1 int
AS
SELECT c.Name, c.Age, c2.Name, c2.Country
FROM Cus C
INNER JOIN Cus2 C2 ON c.id = c2.id
WHERE c2.country is not null and c2.id = #param1
Order by c2.Country
RETURN 0
ID 1
+-----+----+---------+---------+
| QID | ID | Name | Country |
+-----+----+---------+---------+
| 1 | 1 | Null | PH |
| 2 | 1 | Null | CN |
| 3 | 1 | Japhet | USA |
| 4 | 1 | Abegail | UK |
| 5 | 1 | Norlee | Ger |
+-----+----+---------+---------+
ID 2
+-----+----+----------+---------+
| QID | ID | Name | Country |
+-----+----+----------+---------+
| 1 | 2 | Null | PH |
| 2 | 2 | Null | CN |
| 3 | 2 | Reynaldo | USA |
| 4 | 2 | Abegail | UK |
| 5 | 2 | Norlee | Ger |
+-----+----+----------+---------+
ID 3
+-----+----+----------+---------+
| QID | ID | Name | Country |
+-----+----+----------+---------+
| 1 | 3 | Gab | PH |
| 2 | 3 | Null | CN |
| 3 | 3 | Reynaldo | USA |
| 4 | 3 | Abegail | UK |
| 5 | 3 | Norlee | Ger |
+-----+----+----------+---------+
I want when I choose any of the user in the C Table it will display the C child table data and remove the null name rows and remain the rows with not null name column.
Desired Result:
C Table (Parent)
+----+---------+-----+
| ID | Name | Age |
+----+---------+-----+
| 3 | Abegail | 31 |
+----+---------+-----+
C2 Table (Child)
+-----+----+----------+---------+
| QID | ID | Name | Country |
+-----+----+----------+---------+
| 1 | 3 | Gab | PH |
| 3 | 3 | Reynaldo | USA |
| 4 | 3 | Abegail | UK |
| 5 | 3 | Norlee | Ger |
+-----+----+----------+---------+
WHERE column IS NOT NULL is the syntax to filter out NULL values.
Solution 1: test not null value
Example:
WHERE yourcolumn IS NOT NULL
Solution 2: test comparaison value in your where clause (comparaison substract null values)
Examples:
WHERE yourcolumn = value
WHERE yourcolumn <> value
WHERE yourcolumn in ( value)
WHERE yourcolumn not in ( value)
WHERE yourcolumn between value1 and value2
WHERE yourcolumn not between value1 and value2