need some help from count query - mysql

I have a table called
tb_applicants with fields id, aic, name
app_interview with fields id, atic, atname
My problem is i want to count all (atic) from app_interview table where atic is equal to aic from table (tb_applicants) group by 1(aic) from tb_applicants
In my current query its not working can anyone help me find where is the problem it gives me 0 count all the time.
query:
SELECT count(t.atic)
FROM app_interview as t
INNER JOIN tb_applicants as t2
WHERE t.atic = t2.aic
GROUP BY t2.aic;

Remove the ; and use ON for JOINS:
SELECT count(*) FROM app_interview INNER JOIN tb_applicants ON tb_applicants.aic = app_interview.atic GROUP BY tb_applicants.aic;

Could probably done simpler, since you need only matching rows:
SELECT count(t.atic)
FROM app_interview as t, tb_applicants as t2
WHERE t.atic = t2.aic
GROUP BY t.atic;

Related

Mysql - I have 3 unique tables, need a hint on getting the details with the count

I have 3 tables which are interconnected and i want to select columns from two tables and counts from table 3. If anyone is aware on this, any hint would be appreciated.
Below is the sql i tried, but the count is getting repeated
SELECT distinct p.p_id, p.p_f6, p.p_l4,m.m_id, (
SELECT COUNT(*)
FROM ttokens t where t.pdetail_id = p.pdetail_id
) AS token_count
FROM tparking p,ttokens t LEFT join ttokens_md m ON t.trefn_id = m.trefn_id
WHERE t.pdetail_id = p.pdetail_id
You can try to use JOIN with subquery to get your count instead of selcet subquery.
SELECT p.p_id, p.p_f6, p.p_l4,m.m_id,t.cnt
FROM tparking p
JOIN (
SELECT pdetail_id,COUNT(*) cnt
FROM ttokens
GROUP BY pdetail_id
) t ON t.pdetail_id = p.pdetail_id
LEFT join ttokens_md m ON t.trefn_id = m.trefn_id
Note
I would use JOIN instead of , comma with where condition to connect two tables,, is an old style.

LEFT JOIN SUM with WHERE clause

The following query always outputs SUM for all rows instead of per userid. Not sure where else to look. Please help.
SELECT * FROM assignments
LEFT JOIN (
SELECT SUM(timeworked) AS totaltimeworked
FROM time_entries
) assignments ON (userid = assignments.userid AND ticketid = ?)
WHERE ticketid = ?
ORDER BY assigned,scheduled
If you want to keep the SELECT *, you would have to add a group by clause in the subquery. Something like this
SELECT * FROM assignments
LEFT JOIN (
SELECT SUM(timeworked) AS totaltimeworked
FROM time_entries
GROUP BY userid
) time_entriesSummed ON time_entriesSummed.userid = assignments.userid
WHERE ticketid = ?
ORDER BY assigned,scheduled
But a better way would be to change the SELECT * to instead select the fields you want a add a group by clause directly. Something like this
SELECT
assignments.id,
assignments.assigned,
assignments.scheduled,
SUM(time_entries.timeworked) AS totalTimeworked
FROM assignments
LEFT JOIN time_entries
ON time_entries.userid = assignments.userid
GROUP BY assignments.id, assignments.assigned, assignments.scheduled
Edit 1
Included table names in query 2 as mentioned in chameera's comment below

MySQL avoiding GROUP BY columns from different tables

I've the following query that does a group by on 2 columns from different tables. I understand this can cause performance issues. I'm unsure how to go about optimizing this. Any help is greatly appreciated!
Query
SELECT tableA.col AS tableAcol,
tableB.col AS tableBcol,
SUM(tableB.count) AS total
FROM tableB, tableA
WHERE tableB.uid = tableA.uid
AND tableA.eid=?
GROUP BY tableA.col, tableB.col
You can use a subquery that performs partial sums, to reduce the size of the JOIN that sum in the outer query.
SELECT tableA.col AS tableAcol
tableBgrouped.col AS tableBcol,
SUM(tableBgrouped.count) AS total
FROM tableA
JOIN (SELECT uid, col, SUM(count) AS count
FROM tableB
GROUP BY uid, col) AS tableBgrouped
ON tableA.uid = tableBgrouped.uid
WHERE tableA.eid = ?
GROUP BY tableAcol, tableBcol
SELECT A.`col` AS tableAcol
B.`col` AS tableBcol,
SUM(B.`count`) AS total
FROM tableA A
JOIN (SELECT B1.`uid`, B1.`col`, SUM(B1.`count`) AS count
FROM tableB B
GROUP BY B1.`uid`, B1.`col`) AS B
ON A.`uid` = B.`uid`
WHERE A.`eid` = ?
GROUP BY A.`col`, B.`col`

Sql query to combine result of two tables

Currently I am using the following query to display the following result.
SELECT * FROM RouteToGrowthRecord, GradeMaster,MileStoneMaster
WHERE MemberID = 'ALV01L11034A06' AND
RouteToGrowthRecord.GradeID=GradeMaster.GradeID AND
RouteToGrowthRecord.MileStoneID=MileStoneMaster.MileStoneID
ORDER BY CheckupDate DESC
Now I have another table named RouteToGrowthRecord_st that has same
columns as RouteToGrowthRecord with some additional fields.
I need to display result that are present in both the table. ie . if RouteToGrowthRecord_st has 3 records with the given menberID,then output must contain 3 more records along with the above query result.(fr ex above its 9+3=12 records in total).
You can use Union here to merge the results getting from both queries. Use default values for the unmapped additional fields.
You can write above query in following way
SELECT * FROM RouteToGrowthRecord
INNER JOIN GradeMaster ON RouteToGrowthRecord.GradeID=GradeMaster.GradeID
INNER JOIN MileStoneMaster ON RouteToGrowthRecord.MileStoneID=MileStoneMaster.MileStoneID
LEFT JOIN RouteToGrowthRecord_st ON RouteToGrowthRecord_st.memberID=RouteToGrowthRecord.memberID
WHERE
RouteToGrowthRecord.MemberID = 'ALV01L11034A06'
order by CheckupDate DESC
this is my answer
SELECT CheckUpDate,AgeInMonths,PresentWeight,Height,Diagnosis,growthstatus,GradeName,MilestoneName,MemberID
FROM RouteToGrowthRecord, GradeMaster,MileStoneMaster WHERE
MemberID = 'ALV01L56107A11 ' and
RouteToGrowthRecord.GradeID=GradeMaster.GradeID and
RouteToGrowthRecord.MileStoneID=MileStoneMaster.MileStoneID
union
SELECT CheckUpDate,AgeInMonths,PresentWeight,Height,Diagnosis,growthstatus,GradeName,MilestoneName,MemberID
FROM RouteToGrowthRecord_st, GradeMaster,MileStoneMaster WHERE
MemberID = 'ALV01L56107A11 ' and
RouteToGrowthRecord_st.GradeID=GradeMaster.GradeID and
RouteToGrowthRecord_st.MileStoneID=MileStoneMaster.MileStoneID
order by CheckupDate DESC
SELECT * FROM RouteToGrowthRecord a inner join GradeMaster b inner
join MileStoneMaster c inner join RouteToGrowthRecord_st d on
a.GradeID=b.GradeID AND a.MileStoneID=c.MileStoneID and
d.GradeID=b.GradeID AND d.MileStoneID=c.MileStoneID
WHERE a.MemberID = 'ALV01L11034A06'
ORDER BY CheckupDate DESC

MySQL Inner Join with where clause sorting and limit, subquery?

Everything in the following query results in one line for each invBlueprintTypes row with the correct information. But I'm trying to add something to it. See below the codeblock.
Select
blueprintType.typeID,
blueprintType.typeName Blueprint,
productType.typeID,
productType.typeName Item,
productType.portionSize,
blueprintType.basePrice * 0.9 As bpoPrice,
productGroup.groupName ItemGroup,
productCategory.categoryName ItemCategory,
blueprints.productionTime,
blueprints.techLevel,
blueprints.researchProductivityTime,
blueprints.researchMaterialTime,
blueprints.researchCopyTime,
blueprints.researchTechTime,
blueprints.productivityModifier,
blueprints.materialModifier,
blueprints.wasteFactor,
blueprints.maxProductionLimit,
blueprints.blueprintTypeID
From
invBlueprintTypes As blueprints
Inner Join invTypes As blueprintType On blueprints.blueprintTypeID = blueprintType.typeID
Inner Join invTypes As productType On blueprints.productTypeID = productType.typeID
Inner Join invGroups As productGroup On productType.groupID = productGroup.groupID
Inner Join invCategories As productCategory On productGroup.categoryID = productCategory.categoryID
Where
blueprints.techLevel = 1 And
blueprintType.published = 1 And
productType.marketGroupID Is Not Null And
blueprintType.basePrice > 0
So what I need to get in here is the following table with the columns below it so I can use the values timestamp and sort the entire result by profitHour
tablename: invBlueprintTypesPrices
columns: blueprintTypeID, timestamp, profitHour
I need this information with the following select in mind. Using a select to show my intention of the JOIN/in-query select or whatever that can do this.
SELECT * FROM invBlueprintTypesPrices
WHERE blueprintTypeID = blueprintType.typeID
ORDER BY timestamp DESC LIMIT 1
And I need the main row from table invBlueprintTypes to still show even if there is no result from the invBlueprintTypesPrices. The LIMIT 1 is because I want the newest row possible, but deleting the older data is not a option since history is needed.
If I've understood correctly I think I need a subquery select, but how to do that? I've tired adding the exact query that is above with a AS blueprintPrices after the query's closing ), but did not work with a error with the
WHERE blueprintTypeID = blueprintType.typeID
part being the focus of the error. I have no idea why. Anyone who can solve this?
You'll need to use a LEFT JOIN to check for NULL values in invBlueprintTypesPrices. To mimic the LIMIT 1 per TypeId, you can use the MAX() or to truly make sure you only return a single record, use a row number -- this depends on whether you can have multiple max time stamps for each type id. Assuming not, then this should be close:
Select
...
From
invBlueprintTypes As blueprints
Inner Join invTypes As blueprintType On blueprints.blueprintTypeID = blueprintType.typeID
Inner Join invTypes As productType On blueprints.productTypeID = productType.typeID
Inner Join invGroups As productGroup On productType.groupID = productGroup.groupID
Inner Join invCategories As productCategory On productGroup.categoryID = productCategory.categoryID
Left Join (
SELECT MAX(TimeStamp) MaxTime, TypeId
FROM invBlueprintTypesPrices
GROUP BY TypeId
) blueprintTypePrice On blueprints.blueprintTypeID = blueprintTypePrice.typeID
Left Join invBlueprintTypesPrices blueprintTypePrices On
blueprintTypePrice.TypeId = blueprintTypePrices.TypeId AND
blueprintTypePrice.MaxTime = blueprintTypePrices.TimeStamp
Where
blueprints.techLevel = 1 And
blueprintType.published = 1 And
productType.marketGroupID Is Not Null And
blueprintType.basePrice > 0
Order By
blueprintTypePrices.profitHour
Assuming you might have the same max time stamp with 2 different records, replace the 2 left joins above with something similar to this getting the row number:
Left Join (
SELECT #rn:=IF(#prevTypeId=TypeId,#rn+1,1) rn,
TimeStamp,
TypeId,
profitHour,
#prevTypeId:=TypeId
FROM (SELECT *
FROM invBlueprintTypesPrices
ORDER BY TypeId, TimeStamp DESC) t
JOIN (SELECT #rn:=0) t2
) blueprintTypePrices On blueprints.blueprintTypeID = blueprintTypePrices.typeID AND blueprintTypePrices.rn=1
You don't say where you are putting the subquery. If in the select clause, then you have a problem because you are returning more than one value.
You can't put this into the from clause directly, because you have a correlated subquery (not allowed).
Instead, you can put it in like this:
from . . .
(select *
from invBLueprintTypesPrices ibptp
where ibtp.timestamp = (select ibptp2.timestamp
from invBLueprintTypesPrices ibptp2
where ibptp.blueprintTypeId = ibptp2.blueprintTypeId
order by timestamp desc
limit 1
)
) ibptp
on ibptp.blueprintTypeId = blueprintType.TypeID
This identifies the most recent records for all the blueprintTypeids in the subquery. It then joins in the one that matches.