util.sql: Ignore if tables and indices already exist on creation (fixes #1064) Tested with SQLite3 3.16.2 and 3.27.2 and Postgres 11. MySQL does not support IF NOT EXISTS for indices so not handled here.

author: Kim Alvefur <zash@zash.se>
date: Thu, 30 May 2019 23:50:28 +0200
parent: 9616:61376a3c0c1d
child: 10109:c59d384b0959
--- a/util/sql.lua	Thu May 30 15:16:56 2019 +0200
+++ b/util/sql.lua	Thu May 30 23:50:28 2019 +0200
@@ -238,6 +238,9 @@
 end
 function engine:_create_index(index)
 	local sql = "CREATE INDEX \""..index.name.."\" ON \""..index.table.."\" (";
+	if self.params.driver ~= "MySQL" then
+		sql = sql:gsub("^CREATE INDEX", "%1 IF NOT EXISTS");
+	end
 	for i=1,#index do
 		sql = sql.."\""..index[i].."\"";
 		if i ~= #index then sql = sql..", "; end
@@ -256,6 +259,9 @@
 end
 function engine:_create_table(table)
 	local sql = "CREATE TABLE \""..table.name.."\" (";
+	do
+		sql = sql:gsub("^CREATE TABLE", "%1 IF NOT EXISTS");
+	end
 	for i,col in ipairs(table.c) do
 		local col_type = col.type;
 		if col_type == "MEDIUMTEXT" and self.params.driver ~= "MySQL" then