From cec0404cba8ffaaf10057739add6e00e4a304d49 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ren=C3=A9=20Canna=C3=B2?= <rene.cannao@gmail.com>
Date: Tue, 24 Mar 2020 18:11:24 +1100
Subject: [PATCH] Support for LIMIT/OFFSET in SQLite3_result()

---
 include/sqlite3db.h |  3 ++-
 lib/sqlite3db.cpp   | 37 ++++++++++++++++++++++++++++++++-----
 2 files changed, 34 insertions(+), 6 deletions(-)

diff --git a/include/sqlite3db.h b/include/sqlite3db.h
index 0750289e5..75ae9dc5b 100644
--- a/include/sqlite3db.h
+++ b/include/sqlite3db.h
@@ -44,10 +44,11 @@ class SQLite3_result {
 	SQLite3_result(SQLite3_result *);
 	unsigned long long get_size();
 	void add_column_definition(int a, const char *b);
-	int add_row(sqlite3_stmt *stmt);
+	int add_row(sqlite3_stmt *stmt, bool skip=false);
 	int add_row(char **_fields);
 	int add_row(SQLite3_row *old_row);
 	SQLite3_result(sqlite3_stmt *stmt);
+	SQLite3_result(sqlite3_stmt *stmt, int *found_rows, unsigned int offset, unsigned int limit);
 	SQLite3_result(int num_columns, bool en_mutex=false);
 	~SQLite3_result();
 	void dump_to_stderr();
diff --git a/lib/sqlite3db.cpp b/lib/sqlite3db.cpp
index 8c6458f09..537903f0f 100644
--- a/lib/sqlite3db.cpp
+++ b/lib/sqlite3db.cpp
@@ -554,13 +554,15 @@ void SQLite3_result::add_column_definition(int a, const char *b) {
 	column_definition.push_back(cf);
 }
 
-int SQLite3_result::add_row(sqlite3_stmt *stmt) {
+int SQLite3_result::add_row(sqlite3_stmt *stmt, bool skip) {
 	int rc=sqlite3_step(stmt);
 	if (rc!=SQLITE_ROW) return rc;
-	SQLite3_row *row=new SQLite3_row(columns);
-	row->add_fields(stmt);
-	rows.push_back(row);
-	rows_count++;
+	if (skip==false) {
+		SQLite3_row *row=new SQLite3_row(columns);
+		row->add_fields(stmt);
+		rows.push_back(row);
+		rows_count++;
+	}
 	return SQLITE_ROW;
 }
 
@@ -595,6 +597,31 @@ SQLite3_result::SQLite3_result(sqlite3_stmt *stmt) {
 	while (add_row(stmt)==SQLITE_ROW) {};
 }
 
+SQLite3_result::SQLite3_result(sqlite3_stmt *stmt, int * found_rows, unsigned int offset, unsigned int limit) {
+	rows_count=0;
+	int fr = 0;
+	columns=sqlite3_column_count(stmt);
+	for (int i=0; i<columns; i++) {
+		add_column_definition(sqlite3_column_type(stmt,i), sqlite3_column_name(stmt,i));
+	}
+	int rc = SQLITE_ROW;
+	while (offset > 0 && rc==SQLITE_ROW) {
+		rc = add_row(stmt, true);
+		if (rc == SQLITE_ROW) fr++;
+		offset--;
+	}
+	while (limit > 0 && rc==SQLITE_ROW) {
+		rc = add_row(stmt, false);
+		if (rc == SQLITE_ROW) fr++;
+		limit--;
+	}
+	while (rc == SQLITE_ROW) {
+		rc=add_row(stmt, true);
+		if (rc == SQLITE_ROW) fr++;
+	}
+	*found_rows = fr;
+}
+
 SQLite3_result::SQLite3_result(int num_columns, bool en_mutex) {
 	rows_count=0;
 	columns=num_columns;