Add. Extend database API to support parameters. (#2086)

resources/install/scripts/resources/functions/database.lua

@@ -19,6 +19,52 @@ BACKEND.main = BACKEND.main or 'native'
 
 local unpack = unpack or table.unpack
 
+-----------------------------------------------------------
+
+local NULL, DEFAULT = {}, {}
+
+local param_pattern = "[:]([^%d%s][%a%d_]+)"
+
+--
+-- Substitude named parameters to query
+--
+-- @tparam string sql query text
+-- @tparam table params values for parameters
+-- @treturn[1] string new sql query
+-- @treturn[2] nil
+-- @treturn[2] string error message
+--
+local function apply_params(db, sql, params)
+  params = params or {}
+
+  local str = string.gsub(sql, param_pattern, function(param)
+    local v, t = params[param], type(params[param])
+    if "string"  == t then return db:quote(v)      end
+    if "number"  == t then return tostring(v)      end
+    if "boolean" == t then return v and '1' or '0' end
+    if NULL      == v then return 'NULL'           end
+    if DEFAULT   == v then return 'DEFAULT'        end
+    err = "undefined parameter: " .. param
+  end)
+
+  if err then return nil, err end
+
+  return str
+end
+
+local sql_escape
+
+if freeswitch then
+  local api = require "resources.functions.api"
+  sql_escape = function(str)
+    return api:execute('sql_escape', str)
+  end
+else
+  sql_escape = function(str)
+    return (string.gsub(str, "'", "''"))
+  end
+end
+
 -----------------------------------------------------------
 local installed_classes = {}
 local default_backend = FsDatabase
@@ -31,6 +77,10 @@ local function new_database(backend, backend_name)
   Database.__base = backend or default_backend
   Database = setmetatable(Database, Database.__base)
 
+  Database.NULL = NULL
+
+  Database.DEFAULT = NULL
+
   function Database.new(...)
     local self = Database.__base.new(...)
     setmetatable(self, Database)
@@ -40,10 +90,52 @@ local function new_database(backend, backend_name)
   function Database:backend_name()
     return backend_name
   end
-  
-  function Database:first_row(sql)
+
+  function Database:_apply_params(sql, params)
+    return apply_params(self, sql, params)
+  end
+
+  function Database:query(sql, ...)
+    local params, callback
+
+    local argc = select('#', ...)
+
+    if argc > 0 then
+      local p = select(argc, ...)
+      if (p == nil) or (type(p) == 'function') then
+        callback = p
+        argc = argc - 1
+      end
+    end
+
+    if argc > 0 then
+      local p = select(argc, ...)
+      if (p == nil) or (type(p) == 'table') then
+        params = p
+        argc = argc - 1
+      end
+    end
+
+    assert(argc == 0, 'invalid argument #' .. tostring(argc))
+
+    if params then
+      -- backend supports parameters natively
+      if self.__base.parameter_query then
+        return self.__base.parameter_query(self, sql, params, callback)
+      end
+
+      -- use emulation of parametes
+      local err
+      sql, err = self:_apply_params(sql, params)
+      if not sql then return nil, err end
+    end
+
+    return self.__base.query(self, sql, callback)
+  end
+
+  function Database:first_row(sql, params)
     local result
-    local ok, err = self:query(sql, function(row)
+    local ok, err = self:query(sql, params, function(row)
       result = row
       return 1
     end)
@@ -51,21 +143,33 @@ local function new_database(backend, backend_name)
     return result
   end
 
-  function Database:first_value(sql)
-    local result, err = self:first_row(sql)
+  function Database:first_value(sql, params)
+    local result, err = self:first_row(sql, params)
     if not result then return nil, err end
     local k, v = next(result)
     return v
   end
 
   function Database:first(sql, ...)
-    local result, err = self:first_row(sql)
-    if not result then return nil, err end
-    local t, n = {}, select('#', ...)
-    for i = 1, n do
-      t[i] = result[(select(i, ...))]
+    local t = type((...))
+    local has_params = (t == 'nil') or (t == 'table')
+
+    local result, err
+    if has_params then
+      result, err = self:first_row(sql, (...))
+    else
+      result, err = self:first_row(sql)
     end
-    return unpack(t, 1, n)
+
+    if not result then return nil, err end
+
+    local t, n, c = {}, select('#', ...), 0
+    for i = (has_params and 2 or 1), n do
+      c = c + 1
+      t[c] = result[(select(i, ...))]
+    end
+
+    return unpack(t, 1, c)
   end
 
   function Database:fetch_all(sql)
@@ -78,7 +182,7 @@ local function new_database(backend, backend_name)
   end
 
   function Database:escape(str)
-    return (string.gsub(str, "'", "''"))
+    return sql_escape(str)
   end
 
   function Database:quote(str)
@@ -176,6 +280,46 @@ local function new_database(backend, backend_name)
     db:release()
     assert(not db:connected())
 
+    local db = Database.new(...)
+
+    assert(db:connected())
+
+    -- test substitude parameters
+    t = assert(db:first_row('select :p1 as p1, :p2 as p2', {p1 = 'hello', p2 = 'world'}))
+    assert(t.p1 == 'hello')
+    assert(t.p2 == 'world')
+
+    -- test escape string
+    -- `sql_escape` on freeswitch do `trim`
+    if not freeswitch then
+      -- test no trim value
+      local v = " hello "
+      a = assert(db:first_value('select :p1', {p1 = v}))
+      assert(a == v)
+
+      -- test newline 
+      -- On Windows with pgsql it replace `\n` to `\r\n`)
+      local v = "\r\nhello\r\nworld\r\n"
+      a = assert(db:first_value('select :p1', {p1 = v}))
+      assert(a == v, string.format('%q', tostring(a)))
+    end
+
+    -- test backslash
+    local v = "\\hello\\world\\"
+    a = assert(db:first_value('select :p1', {p1 = v}))
+    assert(a == v, string.format('%q', tostring(a)))
+
+    -- test single quote
+    local v = "'hello''world'''"
+    a = assert(db:first_value('select :p1', {p1 = v}))
+    assert(a == v, string.format('%q', tostring(a)))
+
+    -- test empty string
+    local v = ""
+    a = assert(db:first_value('select :p1', {p1 = v}))
+    assert(a == v, string.format('%q', tostring(a)))
+
+    db:release()
     log.info('self_test Database - pass')
   end