I have a list of JSON strings stored in Redis that looks something like this:
[
{ "ID": 25, "DomainID": 23455, "Name": "Stuff", "Value": 23 },
{ "ID": 35, "DomainID": 23455, "Name": "Stuff", "Value": 10 }
]
The key would be something like "Event:23455".
Using a Lua script and ServiceStack.Redis how would I pull out an anonymous object containing only values where the value is less than 20?
So what I want to return would look like this:
[{ "ID": 35, "Value": 10}]
Thanks.
UPDATE 03/31/2013:
After trying what has been suggested I now have a new problem. A Lua script syntax error.
I'm getting a Lua syntax error about "expecting '=' near cjson". Here is the Lua script string (in C#) I am feeding to Redis:
string luaScript = "local tDecoded = cjson.decode(redis.call('GET', KEYS[1]));"
+ "local tFinal = {};"
+ "for iIndex, tValue in ipairs(tDecoded) do"
+ " if tonumber( tValue.Value ) < 20 then"
+ " table.insert(tFinal, { ID = tValue.ID, Value = tValue.Value});"
+ " end"
+ "end"
+ "return cjson.encode(tFinal);";
Are there any Lua or Redis Lua experts out there that can see what might be the problem? i.e. Does the Lua syntax look correct?
UPDATE 04/02/2013
The parsing error was resolved by adding \n newline characters to end of each line like so.
string luaScript = "local tDecoded = redis.call('GET', KEYS[1]);\n"
+ "local tFinal = {};\n"
+ "for iIndex, tValue in ipairs(tDecoded) do\n"
+ " if tonumber( tValue.Value ) < 20 then\n"
+ " table.insert(tFinal, { ID = tValue.ID, Value = tValue.Value});\n"
+ " else\n"
+ " table.insert(tFinal, { ID = 999, Value = 0});\n"
+ " end\n"
+ "end\n"
+ "return cjson.encode(tFinal);";
Unfortunately this works without errors but for some reason only returns "{}" or an empty list in the ServiceStack RedisClient. So I'm not there yet but I am one step closer.