From 434dcd7166361fddd84953d8cdd0de68564096ba Mon Sep 17 00:00:00 2001
From: Milos Negovanovic <milos.negovanovic@gmail.com>
Date: Wed, 20 Aug 2014 10:24:36 +0100
Subject: [PATCH 1/4] Preserve nil <-> NULL between Nimrod and database.

---
 lib/impure/db_mysql.nim | 23 ++++++++++++++++++-----
 1 file changed, 18 insertions(+), 5 deletions(-)

diff --git a/lib/impure/db_mysql.nim b/lib/impure/db_mysql.nim
index eec4daf00d..eb4092f37c 100644
--- a/lib/impure/db_mysql.nim
+++ b/lib/impure/db_mysql.nim
@@ -57,7 +57,7 @@ when false:
       binding: seq[MYSQL_BIND]
     discard mysql_stmt_close(stmt)
 
-proc dbQuote(s: string): string =
+proc dbQuote*(s: string): string =
   result = "'"
   for c in items(s):
     if c == '\'': add(result, "''")
@@ -69,7 +69,10 @@ proc dbFormat(formatstr: TSqlQuery, args: varargs[string]): string =
   var a = 0
   for c in items(string(formatstr)):
     if c == '?':
-      add(result, dbQuote(args[a]))
+      if args[a] == nil:
+        add(result, "NULL")
+      else:
+        add(result, dbQuote(args[a]))
       inc(a)
     else: 
       add(result, c)
@@ -115,7 +118,10 @@ iterator fastRows*(db: TDbConn, query: TSqlQuery,
       if row == nil: break
       for i in 0..L-1: 
         setLen(result[i], 0)
-        add(result[i], row[i])
+        if row[i] == nil:
+          result[i] = nil
+        else:
+          add(result[i], row[i])
       yield result
     properFreeResult(sqlres, row)
 
@@ -132,7 +138,10 @@ proc getRow*(db: TDbConn, query: TSqlQuery,
     if row != nil: 
       for i in 0..L-1: 
         setLen(result[i], 0)
-        add(result[i], row[i])
+        if row[i] == nil:
+          result[i] = nil
+        else:
+          add(result[i], row[i])
     properFreeResult(sqlres, row)
 
 proc getAllRows*(db: TDbConn, query: TSqlQuery, 
@@ -150,7 +159,11 @@ proc getAllRows*(db: TDbConn, query: TSqlQuery,
       if row == nil: break
       setLen(result, j+1)
       newSeq(result[j], L)
-      for i in 0..L-1: result[j][i] = $row[i]
+      for i in 0..L-1:
+        if row[i] == nil:
+          result[j][i] = nil
+        else:
+          result[j][i] = $row[i]
       inc(j)
     mysql.FreeResult(sqlres)
 

From f59ac26b85302808f135aab5309c7683c4b8f405 Mon Sep 17 00:00:00 2001
From: Milos Negovanovic <milos.negovanovic@gmail.com>
Date: Fri, 26 Sep 2014 11:23:13 +0100
Subject: [PATCH 2/4] Tweaks for postgres driver (not tested yet).

---
 lib/impure/db_postgres.nim | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/lib/impure/db_postgres.nim b/lib/impure/db_postgres.nim
index c375d91910..67e769ed20 100644
--- a/lib/impure/db_postgres.nim
+++ b/lib/impure/db_postgres.nim
@@ -60,7 +60,10 @@ proc dbFormat(formatstr: TSqlQuery, args: varargs[string]): string =
   var a = 0
   for c in items(string(formatstr)):
     if c == '?':
-      add(result, dbQuote(args[a]))
+      if args[a] == nil:
+        add(result, "NULL")
+      else:
+        add(result, dbQuote(args[a]))
       inc(a)
     else:
       add(result, c)
@@ -124,7 +127,10 @@ proc setRow(res: PPGresult, r: var TRow, line, cols: int32) =
   for col in 0..cols-1:
     setLen(r[col], 0)
     var x = PQgetvalue(res, line, col)
-    add(r[col], x)
+    if x == nil:
+      r[col] = nil
+    else:
+      add(r[col], x)
 
 iterator fastRows*(db: TDbConn, query: TSqlQuery,
                    args: varargs[string, `$`]): TRow {.tags: [FReadDB].} =

From 11a2cfb306e50d50eb5c9a35864f5dbbfdabe75f Mon Sep 17 00:00:00 2001
From: Milos Negovanovic <milos.negovanovic@gmail.com>
Date: Tue, 21 Oct 2014 15:55:02 +0100
Subject: [PATCH 3/4] Add comment.

---
 lib/impure/db_mysql.nim | 1 +
 1 file changed, 1 insertion(+)

diff --git a/lib/impure/db_mysql.nim b/lib/impure/db_mysql.nim
index eb4092f37c..ce48a32edf 100644
--- a/lib/impure/db_mysql.nim
+++ b/lib/impure/db_mysql.nim
@@ -58,6 +58,7 @@ when false:
     discard mysql_stmt_close(stmt)
 
 proc dbQuote*(s: string): string =
+  ## DB quotes the string.
   result = "'"
   for c in items(s):
     if c == '\'': add(result, "''")

From 2a203e5340654936e3bbe1c0ac392221d15c9aeb Mon Sep 17 00:00:00 2001
From: Milos Negovanovic <milos.negovanovic@gmail.com>
Date: Tue, 21 Oct 2014 15:56:00 +0100
Subject: [PATCH 4/4] Add comment.

---
 lib/impure/db_postgres.nim | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/impure/db_postgres.nim b/lib/impure/db_postgres.nim
index 67e769ed20..510cb8e452 100644
--- a/lib/impure/db_postgres.nim
+++ b/lib/impure/db_postgres.nim
@@ -48,7 +48,8 @@ proc dbError*(msg: string) {.noreturn.} =
   e.msg = msg
   raise e
 
-proc dbQuote(s: string): string =
+proc dbQuote*(s: string): string =
+  ## DB quotes the string.
   result = "'"
   for c in items(s):
     if c == '\'': add(result, "''")