Reading floating numbers from sqlite database in iphone

Question

I need to read floating point decimals from sqlite db

I have created Variable type in database as INTEGER

i am reading with sqlite3_column_int to NSInteger variables

which parts should changed so i can read floating point integers from database

thanks for answers sorry im a newbie in this topics

Answer 1

Declare the fields as a floating point number. From sqllite datatype doc the database type is REAL. This is a 8 byte floating point number which is an Objective-C double, NSDouble or NSNumber type.

Answer 2

There's no such thing as a floating-point integer. They're mutually exclusive on a fundamental level (well floating point numbers can fall on integer boundaries but you get the idea) :P.

But the way to get floats out is by using the sqlite3_column_double(sqlite3_stmt *, int) function.

NSNumber *f = [NSNumber numberWithFloat:(float)sqlite3_column_double(stmt, col)];

Answer 3

For additional information, sqlite3 uses a dynamic data type system. so anything past these:

• NULL
• INTEGER
• REAL
• TEXT
• BLOB

are just hints to sqlite (technically, affinity), and it'll end up deciding on its own what type it is or is not.

http://www.sqlite.org/datatype3.html

the functions that return doubles, ints, etc are part of the sqlite C API try its best to give you what you want.... so what's stored in a column can potentially be converted by sqlite if what you're asking for is different from what's in the db.

http://www.sqlite.org/c3ref/column_blob.html

about midway down, there's a handy table that'll let you know what to expect.