How to retrieve float values from data base

[sijayreddy]

Hi all
For ex am having the table student with fields student name and marks...Where as name is of the type string and marks float value....and having the records
Studentname Marks
aaa 10.5
bbb 15.3
Now am writing the query

Select * from table where Marks=10.5;

But while executing this query am getting 0 results....What can i do...Is there any way to solve this problem....Other than '=' operator for all (>,<,like,In)am getting the result...Please suggest me

[amitpatel66]

Hi all
For ex am having the table student with fields student name and marks...Where as name is of the type string and marks float value....and having the records
Studentname Marks
aaa 10.5
bbb 15.3
Now am writing the query Select * from table where Marks=10.5;
But while executing this query am getting 0 results....What can i do...Is there any way to solve this problem....Other than '=' operator for all (>,<,like,In)am getting the result...Please suggest me

try this:

 
SELECT * from table WHERE ROUND(marks) = ROUND(10.5);
 
 

[sijayreddy]

try this:

 
SELECT * from table WHERE ROUND(marks) = ROUND(10.5);
 
 

i think this may not be correct ...Why because we are using the round function means we are making that Float value as integer...I don't want to compare two integers i want to compare float values...because in my application even 0.4 value makes a lot difference...please tell me the reason for this and what to do...

[mwasif]

Hi sijayreddy,

Welcome to TSDN!!!

Kindly use CODE tags when posting source code.

What is the data type of 'Marks'? I know you have told above, but I want to make sure. There is no problem with your query. Or you can try this

SELECT * FROM table WHERE Marks>=10.5 AND Marks<=10.5;

[sijayreddy]

Hi sijayreddy,

Welcome to TSDN!!!

Kindly use CODE tags when posting source code.

What is the data type of 'Marks'? I know you have told above, but I want to make sure. There is no problem with your query. Or you can try this

SELECT * FROM table WHERE Marks>=10.5 AND Marks<=10.5;

Hi
Hear am giving all the details how i created the table and inserted the data and the query for retrieving the data

     create table ex(name char,mark float,total float);
    insert into ex values ('a',10.5,55.5);
    insert into ex values ('b',1156.66,5656.65);
   select * from ex where mark=10.5;    
   select * from ex where mark=1156.66 ;

for the first query i.e Select * from ex where mark=10.5... getting the correct result but for the second select query select * from ex where mark=1156.66 query browser is returning ZERO result....
Kindly tell me the reason what is the reason for this and how to resolve the problem

[mwasif]

Change data type to DOUBLE using the below query

ALTER TABLE `ex` CHANGE `mark` `mark` DOUBLE( 14, 2 ) NULL DEFAULT NULL

Now test your query

SELECT * FROM ex WHERE mark=1156.66 ;

FLOAT values are not stored as exact values inside computer architecture.

[sijayreddy]

Change data type to DOUBLE using the below query

ALTER TABLE `ex` CHANGE `mark` `mark` DOUBLE( 14, 2 ) NULL DEFAULT NULL

Now test your query

SELECT * FROM ex WHERE mark=1156.66 ;

FLOAT values are not stored as exact values inside computer architecture.

Thank u mwasif...it is working now...

[mwasif]

You are welcome. Postback whenever you need help.