add db module

This commit is contained in:
zongor 2023-09-10 10:24:41 -04:00
parent 2d40445ee3
commit d81fdb055a
2 changed files with 166 additions and 0 deletions

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@ -5,6 +5,7 @@ maintainer = "admin@alfrescocavern.com"
name = "fortran-micro-httpd"
version = "0.1.0"
[build]
link = ["pthread", "libdill"]
auto-examples = true
auto-executables = true
auto-tests = false
@ -16,3 +17,4 @@ implicit-external = false
implicit-typing = false
source-form = "free"
[dependencies]
fortran-sqlite3 = { git = "https://github.com/interkosmos/fortran-sqlite3.git" }

164
fortran/www/src/db.f90 Normal file
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@ -0,0 +1,164 @@
! db.f90
module db
!! Database abstraction layer.
use, intrinsic :: iso_c_binding
use :: sqlite3
implicit none
private
integer, parameter, public :: DB_OK = SQLITE_OK
type, public :: db_type
type(c_ptr) :: ptr = c_null_ptr
end type db_type
public :: db_close
public :: db_open
public :: db_create_users
public :: db_get_users
public :: db_add_user
public :: db_delete_user
private :: db_error
private :: db_exec
contains
integer function db_open(db, path) result(rc)
!! Opens database.
type(db_type), intent(inout) :: db
character(len=*), intent(in) :: path
rc = sqlite3_open(path, db%ptr)
call db_error(rc, 'sqlite3_open()')
end function db_open
integer function db_exec(db, query) result(rc)
!! Executes SQLite query.
type(db_type), intent(inout) :: db
character(len=*), intent(in) :: query
character(len=:), allocatable :: err_msg
rc = sqlite3_exec(db%ptr, query, c_null_ptr, c_null_ptr, err_msg)
call db_error(rc, 'sqlite3_exec()', err_msg)
end function db_exec
integer function db_close(db) result(rc)
!! Closes database.
type(db_type), intent(inout) :: db
rc = sqlite3_close(db%ptr)
call db_error(rc, 'sqlite3_close()')
end function db_close
integer function db_create_users(db) result(rc)
!! Creates database tables.
type(db_type), intent(inout) :: db
! Create table "users".
rc = db_exec(db, "CREATE TABLE users " &
// "(id INTEGER PRIMARY KEY ASC, " &
// "username TEXT, password TEXT, " &
// "apperance TEXT, x_pos INTEGER, " &
// "y_pos INTEGER, last_login INTEGER, " &
// "created INTEGER);")
if (rc /= SQLITE_OK) return
end function db_create_users
integer function db_add_user(db, name) result(rc)
!! Adds student to database.
type(db_type), intent(inout) :: db
character(len=:), intent(in) :: username
character(len=:), intent(in) :: password
character(len=:), intent(in) :: apperance
integer, intent(in) :: x_pos
integer, intent(in) :: y_pos
integer, intent(in) :: last_login
integer, intent(in) :: created
type(c_ptr) :: stmt
! Insert values through prepared statement.
rc = sqlite3_prepare_v2(db%ptr, "INSERT INTO users(username, password, "
//"apperance, x_pos, y_pos, last_login, created) VALUES (?,?,?,?,?,?,?)", stmt)
call db_error(rc, 'sqlite3_prepare_v2()')
rc = sqlite3_bind_text(stmt, 1, username)
call db_error(rc, 'sqlite3_bind_text()')
rc = sqlite3_bind_text(stmt, 2, password)
call db_error(rc, 'sqlite3_bind_text()')
rc = sqlite3_bind_text(stmt, 3, apperance)
call db_error(rc, 'sqlite3_bind_text()')
rc = sqlite3_bind_integer(stmt, 4, x_pos)
call db_error(rc, 'sqlite3_bind_integer()')
rc = sqlite3_bind_integer(stmt, 5, y_pos)
call db_error(rc, 'sqlite3_bind_integer()')
rc = sqlite3_bind_integer(stmt, 6, last_login)
call db_error(rc, 'sqlite3_bind_integer()')
rc = sqlite3_bind_integer(stmt, 7, created)
call db_error(rc, 'sqlite3_bind_integer()')
! Insert bound value into database.
rc = sqlite3_step(stmt)
call db_error(rc, 'sqlite3_step()')
! Clean-up prepared statement.
rc = sqlite3_finalize(stmt)
call db_error(rc, 'sqlite3_finalize()')
end function db_add_student
integer function db_get_users(db) result(rc)
!! Prints number of courses per student to standard output.
type(db_type), intent(inout) :: db
type(c_ptr) :: stmt
character(len=24) :: username
character(len=24) :: password
rc = sqlite3_prepare_v2(db%ptr, &
"SELECT username " // &
"FROM users;", stmt)
call db_error(rc, 'sqlite3_prepare_v2()')
step_loop: do
rc = sqlite3_step(stmt)
select case (rc)
case (SQLITE_ROW)
username = sqlite3_column_text(stmt, 0)
password = sqlite3_column_text(stmt, 1)
print '(a),(a)', username, password
case (SQLITE_DONE)
exit step_loop
case default
call db_error(rc, 'sqlite3_step()')
exit step_loop
end select
end do step_loop
rc = sqlite3_finalize(stmt)
call db_error(rc, 'sqlite3_finalize()')
end function db_get_users
subroutine db_error(code, proc, err_msg)
!! Prints error message.
integer, intent(in) :: code
character(len=*), intent(in), optional :: proc
character(len=*), intent(in), optional :: err_msg
if (code == SQLITE_OK .or. code == SQLITE_DONE) return
if (present(proc) .and. present(err_msg)) then
print '(a, ": ", a, " (", i0, ")")', proc, err_msg, code
return
end if
if (present(proc)) then
print '(a, ": ", i0)', proc, code
return
end if
print '("unknown error: ", i0)', code
end subroutine db_error
end module db