Fix up constants

docs/db2.md

@@ -17,15 +17,28 @@ All the DB2 functions are within the `db2` namespace.
 * `getColumn` - Grab the value of a specific column.
 * `printError` - If the statement has crashed internally, use `db2.printError` to see more information.
 
+### Constant list
+
+* `SQLRETURN`s:
+  * `db2.SQL_SUCCESS`
+  * `db2.SQL_SUCCESS_WITH_INFO`
+  * `db2.SQL_NO_DATA_FOUND`
+  * `db2.SQL_NEED_DATA`
+  * `db2.SQL_NO_DATA`
+  * `db2.SQL_ERROR`
+  * `db2.SQL_INVALID_HANDLE`
+  * `SQL_STILL_EXECUTING`
+* `db2.NULL`
+
 ***
 
 ### `db2.allocEnv()` - Allocate an environment
 
 ##### Notes
 
 * Allocate an environment to connect and run statements in.
-* Returns environment handle as `number`.
 * Always keep the handle stored so you are able to correctly free the environment at the end of the script.
+* Returns environment handle as `number`. Returns `db2.SQL_ERROR` if there was an error.
 
 ```lua
   local env = db2.allocEnv()
@@ -45,7 +58,7 @@ All the DB2 functions are within the `db2` namespace.
 ##### Notes
 
 * Allocate a connection to run statements in.
-* Returns connection handle as `number`.
+* Returns connection handle as `number`. Returns `db2.SQL_ERROR` if there was an error.
 * Always keep the handle stored so you are able to correctly disconnect at the end of the script.
 
 ```lua
@@ -71,6 +84,7 @@ All the DB2 functions are within the `db2` namespace.
 ##### Notes
 
 * Only supports local databases currently. Support for external databases/system with username and password are coming, eventually.
+* Returns SQLRETURN value as `number`.
 
 ```lua
   local env = db2.allocEnv()
@@ -96,7 +110,7 @@ All the DB2 functions are within the `db2` namespace.
 
 ##### Notes
 
-* Returns statement handle as `number`.
+* Returns statement handle as `number`. Returns `db2.SQL_ERROR` if there was an error.
 * Always keep the handle stored so you are able to correctly free/close the statement at the end of the script.
 
 ```lua
@@ -162,7 +176,7 @@ All the DB2 functions are within the `db2` namespace.
 
 ##### Notes
 
-* Returns SQLRETURN value as `number`. (`0` is successful)
+* Returns SQLRETURN value as `number`.
 * To get the columns out of a fetch, use `db2.getColumn(stmt, col, type, len)`.
 
 ```lua

src/ldb2lib.c

@@ -25,7 +25,7 @@ static int db2_allocEnv(lua_State *L) {
   int sqltrue = SQL_TRUE;
 
   if (SQLAllocEnv(&env) == SQL_ERROR) {
-    lua_pushnumber(L, 0); //0 = ERROR
+    lua_pushnumber(L, SQL_ERROR); //0 = ERROR
     return luaL_execresult(L, SQL_ERROR);
 
   } else {
@@ -48,7 +48,7 @@ static int db2_allocConnect(lua_State *L) {
   SQLHDBC hdl = 0;
 
   if (SQLAllocConnect(env, &hdl) != SQL_SUCCESS) {
-    lua_pushnumber(L, 0); //0 = ERROR
+    lua_pushnumber(L, SQL_ERROR); //0 = ERROR
     return luaL_execresult(L, SQL_ERROR);
   } else {
 
@@ -71,7 +71,7 @@ static int db2_Connect(lua_State *L) {
   SQLRETURN res = SQLConnect(hdl, database, SQL_NTS, 0, SQL_NTS, 0, SQL_NTS);
 
   if (res != SQL_SUCCESS) {
-    lua_pushnumber(L, 0); //0 = ERROR
+    lua_pushnumber(L, res);
     return luaL_execresult(L, SQL_ERROR);
   } else {
     SQLINTEGER sqltrue = SQL_TRUE;
@@ -80,7 +80,7 @@ static int db2_Connect(lua_State *L) {
     SQLSetConnectAttr(hdl, SQL_ATTR_DBC_SYS_NAMING, &sqltrue, 0);
     SQLSetConnectAttr(hdl, SQL_ATTR_COMMIT, &nocmt, 0);
 
-    lua_pushnumber(L, 1);
+    lua_pushnumber(L, res);
     return 1;
   }
 }
@@ -94,10 +94,10 @@ static int db2_Disconnect(lua_State *L) {
 
 static int db2_allocStatement(lua_State *L) {
   SQLHDBC hdl = lua_tointeger(L, 1);
-  SQLHSTMT stmt = 0;
+  SQLHSTMT stmt = 0; 
 
   if (SQLAllocStmt(hdl, &stmt) != SQL_SUCCESS) {
-    lua_pushnumber(L, 0); //0 = ERROR
+    lua_pushnumber(L, SQL_ERROR); //0 = ERROR
     return luaL_execresult(L, SQL_ERROR);
   } else {
     lua_pushnumber(L, stmt);
@@ -190,11 +190,6 @@ static const luaL_Reg db2lib[] = {
   {"printError",       db2_printError},
 
   {"NULL", NULL},
-  {"SQLCHAR", NULL},
-  {"SQLVARCHAR", NULL},
-  {"SQLNUMERIC", NULL},
-  {"SQLSMALLINT", NULL},
-  {"SQLDECIMAL", NULL},
 
   {"SQL_SUCCESS", NULL},
   {"SQL_SUCCESS_WITH_INFO", NULL},
@@ -218,21 +213,6 @@ LUAMOD_API int luaopen_db2 (lua_State *L) {
   lua_pushstring(L, null);
   lua_setfield(L, -2, "NULL");
 
-  lua_pushnumber(L, 1);
-  lua_setfield(L, -2, "SQLCHAR");
-
-  lua_pushnumber(L, 1);
-  lua_setfield(L, -2, "SQLVARCHAR");
-
-  lua_pushnumber(L, 2);
-  lua_setfield(L, -2, "SQLNUMERIC");
-
-  lua_pushnumber(L, 3);
-  lua_setfield(L, -2, "SQLSMALLINT");
-
-  lua_pushnumber(L, 4);
-  lua_setfield(L, -2, "SQLDECIMAL");
-
   lua_pushnumber(L, 0);
   lua_setfield(L, -2, "SQL_SUCCESS");