v/vlib/mssql/mssql.v

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2021-05-31 13:08:31 +02:00
module mssql
pub struct Connection {
mut:
henv C.SQLHENV = C.SQLHENV(C.SQL_NULL_HENV) // Environment
hdbc C.SQLHDBC = C.SQLHDBC(C.SQL_NULL_HDBC) // Connection handle
pub mut:
conn_str string
}
// connect to db
pub fn (mut conn Connection) connect(conn_str string) ?bool {
conn_str_c := unsafe { &C.SQLCHAR(conn_str.str) }
mut retcode := C.SQLRETURN(C.SQL_SUCCESS)
// Allocate environment handle
retcode = C.SQLAllocHandle(C.SQLSMALLINT(C.SQL_HANDLE_ENV), C.SQLHANDLE(C.SQL_NULL_HANDLE),
unsafe { &C.SQLHANDLE(&conn.henv) })
check_error(retcode, 'SQLAllocHandle(SQL_HANDLE_ENV)', C.SQLHANDLE(conn.henv), C.SQLSMALLINT(C.SQL_HANDLE_ENV)) ?
// Set the ODBC version environment attribute
retcode = C.SQLSetEnvAttr(conn.henv, C.SQLINTEGER(C.SQL_ATTR_ODBC_VERSION), &C.SQLPOINTER(C.SQL_OV_ODBC3),
C.SQLINTEGER(0))
check_error(retcode, 'SQLSetEnvAttr(SQL_ATTR_ODBC_VERSION)', C.SQLHANDLE(conn.henv),
C.SQLSMALLINT(C.SQL_HANDLE_ENV)) ?
// Allocate connection handle
retcode = C.SQLAllocHandle(C.SQLSMALLINT(C.SQL_HANDLE_DBC), C.SQLHANDLE(conn.henv),
unsafe { &C.SQLHANDLE(&conn.hdbc) })
check_error(retcode, 'SQLAllocHandle(SQL_HANDLE_DBC)', C.SQLHANDLE(conn.hdbc), C.SQLSMALLINT(C.SQL_HANDLE_DBC)) ?
// Set login timeout to 5 seconds
retcode = C.SQLSetConnectAttr(conn.hdbc, C.SQLINTEGER(C.SQL_LOGIN_TIMEOUT), C.SQLPOINTER(5),
C.SQLINTEGER(0))
check_error(retcode, 'SQLSetConnectAttr(SQL_LOGIN_TIMEOUT)', C.SQLHANDLE(conn.hdbc),
C.SQLSMALLINT(C.SQL_HANDLE_DBC)) ?
// Connect to data source
mut outstr := [1024]char{}
mut outstrlen := C.SQLSMALLINT(0)
retcode = C.SQLDriverConnect(conn.hdbc, C.SQLHWND(0), conn_str_c, C.SQLSMALLINT(C.SQL_NTS),
&C.SQLCHAR(&outstr[0]), C.SQLSMALLINT(sizeof(outstr)), &outstrlen, C.SQLUSMALLINT(C.SQL_DRIVER_NOPROMPT))
check_error(retcode, 'SQLDriverConnect()', C.SQLHANDLE(conn.hdbc), C.SQLSMALLINT(C.SQL_HANDLE_DBC)) ?
conn.conn_str = conn_str
return true
}
// close - closes the connection.
pub fn (mut conn Connection) close() {
// Connection
if conn.hdbc != C.SQLHDBC(C.SQL_NULL_HDBC) {
C.SQLDisconnect(conn.hdbc)
C.SQLFreeHandle(C.SQLSMALLINT(C.SQL_HANDLE_DBC), C.SQLHANDLE(conn.hdbc))
conn.hdbc = C.SQLHDBC(C.SQL_NULL_HDBC)
}
// Environment
if conn.henv != C.SQLHENV(C.SQL_NULL_HENV) {
C.SQLFreeHandle(C.SQLSMALLINT(C.SQL_HANDLE_ENV), C.SQLHANDLE(conn.henv))
conn.henv = C.SQLHENV(C.SQL_NULL_HENV)
}
}
// query executes a sql query
pub fn (mut conn Connection) query(q string) ?Result {
mut hstmt := new_hstmt(conn.hdbc) ?
defer {
hstmt.close()
}
hstmt.exec(q) ?
affected := hstmt.retrieve_affected_rows() ?
hstmt.prepare_read() ?
raw_rows := hstmt.read_rows() ?
mut res := Result{
rows: []Row{}
num_rows_affected: affected
}
for rr in raw_rows {
res.rows << Row{
vals: rr
}
}
return res
}
// check_error checks odbc return code and extract error string if available
fn check_error(e C.SQLRETURN, s string, h C.SQLHANDLE, t C.SQLSMALLINT) ? {
if e != C.SQLRETURN(C.SQL_SUCCESS) && e != C.SQLRETURN(C.SQL_SUCCESS_WITH_INFO) {
err_str := extract_error(s, h, t)
return error(err_str)
}
}
// extract_error extracts error string from odbc
fn extract_error(fnName string, handle C.SQLHANDLE, tp C.SQLSMALLINT) string {
mut err_str := fnName
mut i := 0
mut native_error := C.SQLINTEGER(0)
mut sql_state := [7]char{}
mut message_text := [256]char{}
mut text_length := C.SQLSMALLINT(0)
mut ret := C.SQLRETURN(C.SQL_SUCCESS)
for ret == C.SQLRETURN(C.SQL_SUCCESS) {
i++
ret = C.SQLGetDiagRec(tp, handle, C.SQLSMALLINT(i), &C.SQLCHAR(&sql_state[0]),
&native_error, &C.SQLCHAR(&message_text[0]), C.SQLSMALLINT(sizeof(message_text)),
&text_length)
// add driver error string
if ret == C.SQLRETURN(C.SQL_SUCCESS) || ret == C.SQLRETURN(C.SQL_SUCCESS_WITH_INFO) {
unsafe {
state_str := (&sql_state[0]).vstring()
native_error_code := int(native_error)
txt_str := (&message_text[0]).vstring()
err_str += '\n\todbc=$state_str:$i:$native_error_code:$txt_str'
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}
}
}
return err_str
}