如何使用luasql创建Sqlite3数据库?

问题描述

我正在尝试使用luasql创建Sqlite3数据库. 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?

此外，我似乎找不到luasql的手册.它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将自动创建该数据库.

SQLLite will create the db automatically if it does not exist.

这里是在Lua中使用它的一组示例函数(忽略它们只是我使用的程序的内部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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