My problem is that I want to apply the following two commands in JavaFX in order to get how many 1ones are in a named "party" column from a database named "conteo".
sql ="select count(*) from conteo where party =1";
ResultSet rs = conn.createStatement().executeQuery(sql);
i used System.out.println(rs.getString("party")); to expect the correct number of 1ones in "party" column from "conteo" database and i get "the error column party do not exist", but actually it already exist!!!
sql ="select count(*) from conteo where party =1";
ResultSet rs = conn.createStatement().executeQuery(sql);
I would like to print in command line "rs" using "System.out.println()"
My database address is correctly address it, because i already write data sucessfully in mysql databases using javafx, how can i properly print "rs" result in command line?, anyhelp is appreciated, thanks in advance, Omar Torres
You asked...
how can i properly print "rs" result
Do you mean something like this...
if (rs.next()) {
int theCount = rs.getInt(1);
System.out.println(theCount);
}
You did not select the party column for the output. Since you're using a aggregate function, this shouldn't work in this case anyways. You'd need to use GROUPING BY+HAVING anyways.
It's much simpler to provide an alias for the value
sql ="SELECT COUNT(*) AS num FROM conteo WHERE party =1";
ResultSet rs = conn.createStatement().executeQuery(sql);
if (rs.next()) {
int i = rs.getInt("num");
...
}
or
sql ="SELECT COUNT(*) FROM conteo WHERE party =1";
ResultSet rs = conn.createStatement().executeQuery(sql);
if (rs.next()) {
int i = rs.getInt(1); // access first column in result
...
}
Related
This is my code.. Query working when i search with mysql query(find it in screenshot).But failed with hiberbate query.
EmployeeAttendanceMaster masterEmployeeFromRepository = masterEmployeeRepository.findById(employee, date);
if (masterEmployeeFromRepository == null) {
System.out.println("SignIn Successfully");
}else System.out.println("You are already Logged In");
masterEmployeeRepository:
#Query("select me from EmployeeAttendanceMaster me where me.employee = ?1 and Date(me.date) = ?2 order by me.date desc")
EmployeeAttendanceMaster findById(Employee employee,Date date);
mysql db screenshot in with same query
Data with same date there in db..So it shoudnot go through if condition.It should follow else condition.But as long as i tried this it prints "SignIn Successfully"
Thanks advance
You are using the Spring Data JPA #Query annotation (as discerned from the full data type you have provided in the comments to your question). The query you specify with #Query (select me from EmployeeAttendanceMaster me ...) must be a valid JPA Query Language (JPQL) statement. From what I know and remember, JPQL does not have a Date() function. So, your query is invalid because it contains Date(me.date) which refers to a non-existent JPQL Date() function, even if you can run it directly on MySQL.
You can change your query declaration to:
#Query(value = "select * from EmployeeAttendanceMaster where employee_id = ?1 and Date(date) = ?2 order by date desc", nativeQuery = true)
This will force the JPA provider (Hibernate in your case) to treat the query as a native SQL query and will be executed on the underlying database without any translation. You will lose database independence though.
I want to recuperate all rows from user table.
String queryS = "select u from user u";
System.out.println("entityManager: "+(entityManager == null));
Query query = entityManager.createQuery(queryS);
//staff
The line that throws the exception is Query query = entityManager.createQuery(queryS);
I don't know why even persistance file is ok and the table exists
The stack is:
10:36:06.693 [AWT-EventQueue-0] DEBUG org.hibernate.hql.ast.ErrorCounter - throwQueryException() : no errors
10:36:06.693 [AWT-EventQueue-0] DEBUG o.h.hql.antlr.HqlSqlBaseWalker - select << begin [level=1, statement=select]
You have to put the name of the table in the query as in the persistence file not in database.
If this:
String queryS = "select u from user u"
Is referred on table name you can't use createQuery method but createNativeQuery
If you want to use createQuery you must use in your query the entity/class mapped youe user table
Summarizing:
Case 1 (use createNativeQuery)
String queryS = "select u from user u";
Query query = entityManager.createNativeQuery(queryS);
Case 2 (use createQuery)
String queryS = "select u from " + User.class.getName() + " u";
Query query = entityManager.createNativeQuery(queryS);
Good Afternoon to All,
I have a question concerning on SQL Queries. is it possible to use an array as a parameter to a query using the "IN" command?
for example,
int x = {2,3,4,5}
UPDATE 'table_name' set 'field' = data WHERE field_ID IN (x)
the reason I am asking this is to avoid an iterative SQL Statement when I have to update data in a database.
I also thought of using a for each statement in for the UPDATE Query but I don't know if it will affect the performance of the query if it will slow down the system if ever 100+ records are updated.
I am using VB.Net btw.
My Database is MySQL Workbench.
I have gotten the answer. I just simply need to convert each elements to a String then concatenate it with a "," for each element. so the parameter that i will pass will be a string.
ANSWER:
int x = {2,3,4,5}
will become
string x = "2,3,4,5"
My Query string will become "UPDATE tablename SET field=value WHERE ID IN("&x&")"
Thank you to all who helped.
If you have the query in a variable (not a stored procedure) and you don't have a huge amount of ids, you could built your own IN. I haven't tested the speed of this approach.
This code won't compile, it's just to give you an idea.
query = "SELECT * FROM table WHERE col IN ("
For t = 0 TO x.Length-1
If t > 0 Then query &= ","
query &= "#var" & t
Next
query &= ")"
...
For t = 0 TO x.Length-1
cmd.Parameters.Add("#var" & t, SqlDbType.Int).Value = x(t)
Next
i am not familiar with mySQL, but when dealing with MSSQL, I normally have a split function in DB so that I can use it to split concatenated integer values as a table, at VB side, something like:
Dim myIds = {1, 2, 3, 4}
Dim sql = <sql>
SELECT m.* FROM dbo.tblMyData m
INNER JOIN dbo.fncSplitIntegerValues(#Ids, ',') t ON t.id = m.Id
</sql>.Value
Using con As New SqlConnection("My connection string..."),
cmd As New SqlCommand(sql, con)
cmd.Parameters.Add("#Ids", SqlDbType.VarChar).Value =
myIds.Select(Function(m) m.ToString).Aggregate(Function(m, n) m & "," & n)
con.Open()
Dim rdr = cmd.ExecuteReader(CommandBehavior.CloseConnection)
While rdr.Read()
Console.WriteLine(rdr.GetValue(0))
' do something else...
End While
End Using
dbo.fncSplitIntegerValues is a db function to split concatenated integer varchar into integer Id with given separator.
it's important not to use plain sql, instead, use sql parameters.
Note: above sample is not tested...
In VB 2010 I'm trying to show the DisplayMember in ProperCase without modifying my existing MySQL tables.
A snippet of my code looks like this:
Dim sql0 As String = "SELECT business, customer_id FROM customers WHERE cab = '1'"
Dim data0 As New MySqlDataAdapter(sql0, main.conn)
Dim ds0 As New DataSet
ds0.Clear()
data0.Fill(ds0, "customers")
cmb_company.DataSource = ds0
cmb_company.DisplayMember = "customers.business"
cmb_company.ValueMember = "customers.customer_id"
Ive tried something like this:
cmb_company.DisplayMember = StrConv("customers.business_name", VbStrConv.ProperCase)
but this only changes the case of the part in quotes, and not the actual returned values. I also tried querying from MySQL like this:
"SELECT UPPER(business), customer_id FROM customers WHERE cab = '1'"
but this fails to return the "business" field..
I'd love it if my combobox had proper case without changing everything.
I appreciate any suggestions!
Use the second one, but use an alias like this:
"SELECT UPPER(business) AS Business, customer_id FROM customers WHERE cab = '1'"
MySQL documentation:
A select_expr can be given an alias using AS alias_name. The alias is
used as the expression's column name and can be used in GROUP BY,
ORDER BY, or HAVING clauses. For example:
SELECT CONCAT(last_name,', ',first_name) AS full_name FROM mytable
ORDER BY full_name;
It seems a bit silly to use a while loop to achieve this especially after filling the table with an adapter. I suppose I could have just skipped the .fill and added the items manually through the loop, all while ProperCasing them. Anyway, here is my code:
Dim sql1 As String = "SELECT * FROM table"
Dim data1 As New MySqlDataAdapter(sql1, main.conn)
Dim ds1 As New DataSet
ds1.Clear()
data1.Fill(ds1, "table")
cmb_buyout.DataSource = ds1
Dim i As Integer = 0
While i < ds1.Tables(0).Rows.Count
Dim name As String = StrConv(ds1.Tables(0).Rows(i).Item(1).ToString, VbStrConv.ProperCase)
ds1.Tables(0).Rows(i).Item(1) = name
i += 1
End While
cmb_buyout.DisplayMember = "table.buyoutType"
cmb_buyout.ValueMember = "table.id"
To anyone trying to accomplish this, it is probably simpler to just change the case on the entries in the DB. I might just end up doing this!
The hibernate manual says this:
String sql = "SELECT ID as {c.id}, NAME as {c.name}, " +
"BIRTHDATE as {c.birthDate}, MOTHER_ID as {c.mother}, {mother.*} " +
"FROM CAT_LOG c, CAT_LOG m WHERE {c.mother} = c.ID";
List loggedCats = sess.createSQLQuery(sql)
.addEntity("cat", Cat.class)
.addEntity("mother", Cat.class).list()
Now, what I have is basically the same. I am return two of the same type per row. I am doing a select something like this:
SELECT {ctrl1.*}, {ctrl2.*} FROM tableA AS A
LEFT JOIN tableB AS ctrl1 ON (A.controlID = ctrl1.controlID AND ctrl1.controlOptionType = ? AND ctrl1.controlOptionValue = ?)
LEFT JOIN tableB AS ctrl2 ON (A.controlID = ctrl2.controlID AND ctrl2.controlOptionType = ? AND ctrl2.controlOptionValue = ?)
And then I addEntity("ctrl1", typeof(mycontrolclass) and
addEntity("ctrl1", typeof(mycontrolclass)
Which seems exactly the same to me as their example. But I get this exception:
"Could not execute query" and the inner exception is "Could not find specified column in results".
If I copy the sql in the exception(to which it has added "AS ctrl1_1_3_3_" etc) it works fine.
Thanks.
What exactly are you trying to do? I believe you might not need using either of them.
// Using HQL:
var motherId = 25;
var hql = "select c.birthDate, c.mother from Cat c where c.mother.Id = :motherId";
var result = Session.CreateQuery(hql)
.SetParameter("motherId", motherId)
.ToList();
// Using NHibernate.LINQ:
var result = (from cat in Session.Linq<Cat>()
where cat.Mother.Id == motherId
select new { cat.birthDate, cat.mother }).ToList();
HQL query examples.
LINQ for NHibernate examples.
I dealt with your problem just for studying purposes, because you will surely
have found a solution in the meanwhile, but the problem should not lie in
the query (which is ok), but in some mapping inconsistency or somewhere else
(perhaps Database).