如何使用 luasql 创建 Sqlite3 数据库?
我正在尝试使用 luasql 创建一个 Sqlite3 数据库.在我require
luasql.sqlite3 之后,如何在文件上创建数据库?
I am trying to create a Sqlite3 database with luasql. After I require
luasql.sqlite3, how do I create the database on a file?
另外,我似乎找不到 luasql 的手册.可以在任何地方使用吗?
Also, I can't seem to find the manual for luasql. Is it available anywhere?
推荐答案
如果数据库不存在,SQLLite 会自动创建.
SQLLite will create the db automatically if it does not exist.
这是一组在 Lua 中使用它的示例函数(忽略它们只是我使用的程序内部的 fh 函数).
Here is a set of Sample functions for using it in Lua (ignore the fh functions they are just internal to the program I use).
require 'luasql.sqlite3'
function opendb(dbname)
-- Check for Settings Database and create if needed
local db = fhGetPluginDataFileName()
local dbenv = assert (luasql.sqlite3())
-- connect to data source, if the file does not exist it will be created
dbcon = assert (dbenv:connect(db))
-- check table for page list
checkTable(dbcon,'pagelist',
[[CREATE TABLE pagelist(filename varchar(500), md5hash varchar(32),UNIQUE (filename))
]])
-- create table for settings
checkTable(dbcon,'settings',
[[CREATE TABLE settings(key varchar(20), directory varchar(500),
host varchar(500), folder varchar(50), userid varchar(50), password varchar(50), UNIQUE (key))
]])
return dbenv,dbcon
end
function checkTable(dbcon,table,createString)
local sql = string.format([[SELECT count(name) as count FROM sqlite_master WHERE type='table' AND name='%s']],table)
local cur = assert(dbcon:execute(sql))
local rowcount = cur:fetch (row, "a")
cur:close()
if tonumber(rowcount) == 0 then
-- Table not found create it
res,err = assert(dbcon:execute(createString))
end
end
function closedb(dbenv,dbcon)
dbcon:close()
dbenv:close()
end
function loadSettings(dbcon)
local sql = [[SELECT * FROM settings]]
local cur,err = assert(dbcon:execute(sql))
local row = cur:fetch({},'a')
cur:close()
if row then
return row
else
-- return default values
return {
directory = fhGetContextInfo('CI_PROJECT_PUBLIC_FOLDER')..'\FH Website',
host = 'websitehost',
folder = '/',
userid = 'user',
password = 'password',
new = 'yes'
}
end
end
function saveSettings(dbcon,settings)
-- Check for Settings
if settings.new == 'yes' then
-- Create
sql = string.format([[insert into settings (directory, host, folder, userid, password) Values('%s','%s','%s','%s','%s')]],settings.directory,settings.host,settings.folder,settings.userid,settings.password)
else
-- Update
sql = string.format([[update settings set directory = '%s', host = '%s',folder = '%s',userid = '%s', password = '%s']],settings.directory,settings.host,settings.folder,settings.userid,settings.password)
end
local res = assert(dbcon:execute(sql))
end
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