From 5967ebf3b75bb5817199178263b9cddab459af1d Mon Sep 17 00:00:00 2001
From: Jonathan Schleifer <js@nil.im>
Date: Thu, 1 Oct 2020 23:43:39 +0000
Subject: [PATCH] Add support for retrieving columns

FossilOrigin-Name: 727a6838a567ab678c28cb0dfc2b95aaa4fa9b5af7b29e9f9833ffd81cea8d9d
---
 src/SL3PreparedStatement.h |  5 +++-
 src/SL3PreparedStatement.m | 48 +++++++++++++++++++++++++++++++++++++-
 tests/Tests.m              | 31 ++++++++++++++++++++++++
 3 files changed, 82 insertions(+), 2 deletions(-)

diff --git a/src/SL3PreparedStatement.h b/src/SL3PreparedStatement.h
index aede8fe..73480fa 100644
--- a/src/SL3PreparedStatement.h
+++ b/src/SL3PreparedStatement.h
@@ -41,7 +41,10 @@ OF_ASSUME_NONNULL_BEGIN
 - (void)bindWithDictionary:
     (OFDictionary OF_GENERIC(OFString *, id) *)dictionary;
 - (void)clearBindings;
-- (void)step;
+- (id)objectForColumn: (size_t)column;
+- (size_t)columnCount;
+- (OFString *)nameForColumn: (size_t)column;
+- (bool)step;
 - (void)reset;
 @end
 
diff --git a/src/SL3PreparedStatement.m b/src/SL3PreparedStatement.m
index 8fa6d34..e979092 100644
--- a/src/SL3PreparedStatement.m
+++ b/src/SL3PreparedStatement.m
@@ -161,7 +161,7 @@ bindObject(SL3PreparedStatement *statement, int column, id object)
 				 errorCode: code];
 }
 
-- (void)step
+- (bool)step
 {
 	int code = sqlite3_step(_stmt);
 
@@ -169,6 +169,52 @@ bindObject(SL3PreparedStatement *statement, int column, id object)
 		@throw [SL3ExecuteStatementFailedException
 		    exceptionWithStatement: self
 				 errorCode: code];
+
+	return (code == SQLITE_ROW);
+}
+
+- (id)objectForColumn: (size_t)column
+{
+	if (column > INT_MAX)
+		@throw [OFOutOfRangeException exception];
+
+	switch (sqlite3_column_type(_stmt, column)) {
+	case SQLITE_INTEGER:
+		return [OFNumber numberWithLongLong:
+		    sqlite3_column_int64(_stmt, column)];
+	case SQLITE_FLOAT:
+		return [OFNumber numberWithDouble:
+		    sqlite3_column_double(_stmt, column)];
+	case SQLITE_TEXT:
+		return [OFString stringWithUTF8String:
+		    (const char *)sqlite3_column_text(_stmt, column)];
+	case SQLITE_BLOB:
+		return [OFData
+		    dataWithItems: sqlite3_column_blob(_stmt, column)
+			    count: sqlite3_column_bytes(_stmt, column)];
+	case SQLITE_NULL:
+		return [OFNull null];
+	default:
+		OF_ENSURE(0);
+	}
+}
+
+- (size_t)columnCount
+{
+	return sqlite3_column_count(_stmt);
+}
+
+- (OFString *)nameForColumn: (size_t)column
+{
+	const char *name;
+
+	if (column > [self columnCount])
+		@throw [OFOutOfRangeException exception];
+
+	if ((name = sqlite3_column_name(_stmt, column)) == NULL)
+		@throw [OFOutOfMemoryException exception];
+
+	return [OFString stringWithUTF8String: name];
 }
 
 - (void)reset
diff --git a/tests/Tests.m b/tests/Tests.m
index 4e71719..6c224ac 100644
--- a/tests/Tests.m
+++ b/tests/Tests.m
@@ -64,6 +64,37 @@ OF_APPLICATION_DELEGATE(Tests)
 	    nil]];
 	[stmt step];
 
+	stmt = [conn prepareStatement: @"SELECT * FROM test"];
+	for (size_t i = 0; [stmt step]; i++) {
+		OF_ENSURE([stmt columnCount] == 3);
+		OF_ENSURE([[stmt nameForColumn: 0] isEqual: @"a"]);
+		OF_ENSURE([[stmt nameForColumn: 1] isEqual: @"b"]);
+		OF_ENSURE([[stmt nameForColumn: 2] isEqual: @"c"]);
+
+		switch (i) {
+		case 0:
+			OF_ENSURE([[stmt objectForColumn: 0]
+			    isEqual: [OFNumber numberWithInt: 5]]);
+			OF_ENSURE([[stmt objectForColumn: 1]
+			    isEqual: @"String"]);
+			OF_ENSURE([[stmt objectForColumn: 2]
+			    isEqual: [OFData dataWithItems: "abc"
+						     count: 3]]);
+			break;
+		case 1:
+			OF_ENSURE([[stmt objectForColumn: 0]
+			    isEqual: [OFNumber numberWithInt: 7]]);
+			OF_ENSURE([[stmt objectForColumn: 1]
+			    isEqual: @"Test"]);
+			OF_ENSURE([[stmt objectForColumn: 2]
+			    isEqual: [OFData dataWithItems: "xyz"
+						     count: 3]]);
+			break;
+		default:
+			OF_ENSURE(0);
+		}
+	}
+
 	[OFApplication terminate];
 }
 @end