hiimray-co-uk-www-posts/2019/03/SQLiteDatabase.cs

470 lines
10 KiB
C#

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Data.SQLite;
using System.IO;
using System.Text;
namespace RyzStudio.Data.SQLite
{
public class SQLiteDatabase
{
public SQLiteConnection DBConnection { get; protected set; } = null;
public string DBLocation { get; protected set; } = null;
public string LastError { get; protected set; } = null;
public int LastInsertID
{
get
{
if (this.DBConnection == null)
{
return 0;
}
DataTable dt = this.DoQuery("SELECT last_insert_rowid() AS rv;");
if (dt == null)
{
return 0;
}
if (dt.Rows.Count <= 0)
{
return 0;
}
int n;
if (!int.TryParse(dt.Rows[0]["rv"].ToString(), out n))
{
n = 0;
}
return n;
}
}
protected string[] requiredTableList = new string[0];
protected const string appSettingsTableName = "ryz_app_xxxx_config";
public bool Create()
{
this.LastError = string.Empty;
this.DBLocation = ":memory:";
try
{
this.DBConnection = new SQLiteConnection(string.Concat("Data Source=\"", this.DBLocation, "\";Version=3;UTF8Encoding=True;"));
this.DBConnection.Open();
}
catch (Exception exc)
{
this.LastError = exc.Message;
return false;
}
return true;
}
public bool Create(string filename, bool overwriteFile = false, string password = null, bool useAppSettings = false)
{
bool rs = create(filename, overwriteFile, password);
if (useAppSettings)
{
if (!rs)
{
return false;
}
rs = prepareDatabase();
if (!rs)
{
return false;
}
return this.HasRequiredTables();
}
else
{
return rs;
}
}
public bool LoadFile(string filename, string password = null)
{
this.LastError = string.Empty;
if (!File.Exists(filename))
{
return false;
}
this.DBLocation = filename;
try
{
this.DBConnection = new SQLiteConnection(string.Concat("Data Source=\"", filename, "\";Version=3;UTF8Encoding=True;", (password == null) ? string.Empty : string.Concat("Password=", encode64(password), ";")));
this.DBConnection.Open();
}
catch (Exception exc)
{
this.LastError = exc.Message;
return false;
}
return true;
}
public void Close()
{
this.LastError = string.Empty;
if (this.DBConnection != null)
{
try
{
this.DBConnection.Cancel();
this.DBConnection.Close();
this.DBConnection.Dispose();
this.DBConnection = null;
SQLiteConnection.ClearAllPools();
GC.Collect();
}
catch (Exception exc)
{
this.LastError = exc.Message;
}
}
}
public DataTable DoQuery(string query)
{
this.LastError = string.Empty;
if (this.DBConnection == null)
{
return null;
}
try
{
SQLiteCommand command = new SQLiteCommand(query, this.DBConnection);
SQLiteDataReader dr = command.ExecuteReader();
DataTable dt = new DataTable();
dt.Load(dr);
return dt;
}
catch (Exception exc)
{
this.LastError = exc.Message;
return null;
}
}
public DataTable DoQuery(string query, params string[] args) => DoQuery(prepareQuery(query, args));
public int DoQueryCount(string query)
{
this.LastError = string.Empty;
if (this.DBConnection == null)
{
return -1;
}
DataTable dt = this.DoQuery(query);
if (dt == null)
{
return -1;
}
return dt.Rows.Count;
}
public int DoQueryCount(string query, params string[] args) => this.DoQueryCount(prepareQuery(query, args));
public bool DoQueryExist(string query) => (this.DoQueryCount(query) > 0);
public bool DoQueryExist(string query, params string[] args) => this.DoQueryExist(prepareQuery(query, args));
public string DoQuerySingle(string query)
{
this.LastError = string.Empty;
if (this.DBConnection == null)
{
return string.Empty;
}
DataTable dt = this.DoQuery(query);
if (dt == null)
{
return string.Empty;
}
if (dt.Columns.Count <= 0)
{
return string.Empty;
}
if (dt.Rows.Count <= 0)
{
return string.Empty;
}
if (dt.Rows[0][0] is byte[])
{
return Encoding.UTF8.GetString(dt.Rows[0][0] as byte[]);
}
else
{
return dt.Rows[0][0].ToString();
}
}
public string DoQuerySingle(string query, params string[] args) => this.DoQuerySingle(prepareQuery(query, args));
public int DoNonQuery(string query)
{
this.LastError = string.Empty;
if (this.DBConnection == null)
{
return -1;
}
int rv = 0;
try
{
SQLiteCommand command = new SQLiteCommand(query, this.DBConnection);
rv = command.ExecuteNonQuery();
}
catch (Exception exc)
{
this.LastError = exc.Message;
rv = -1;
}
return rv;
}
public int DoNonQuery(string query, params string[] args) => this.DoNonQuery(prepareQuery(query, args));
public bool HasTable(string tableName)
{
this.LastError = string.Empty;
if (this.DBConnection == null)
{
return false;
}
int rv = this.DoQueryCount("SELECT 1 FROM sqlite_master WHERE type='table' AND name='" + escapeSQL(tableName) + "'");
return (rv > 0);
}
public bool HasRequiredTables()
{
bool rv = true;
foreach (string tbl in requiredTableList)
{
if (string.IsNullOrEmpty(tbl))
{
continue;
}
if (!this.HasTable(tbl))
{
rv = false;
break;
}
}
return rv;
}
public bool SetConfig(string name, bool value) => this.SetConfig(name, (value ? "1" : "0"));
public bool SetConfig(string name, int value) => this.SetConfig(name, value.ToString());
public bool SetConfig(string name, string value)
{
prepareAppSettings();
string sql = string.Empty;
int rv = this.DoQueryCount("SELECT 1 FROM " + appSettingsTableName + " WHERE cfg_name='" + escapeSQL(name) + "'");
if (rv <= 0)
{
sql = "INSERT INTO " + appSettingsTableName + " (cfg_name, cfg_value) VALUES ('[^1]', '[^2]');";
}
else
{
sql = "UPDATE " + appSettingsTableName + " SET cfg_value='[^2]' WHERE cfg_name='[^1]';";
}
sql = prepareQuery(sql, new string[] { name, value });
return this.DoNonQuery(sql) > 0;
}
public string GetConfig(string name, string defaultValue = null)
{
prepareAppSettings();
bool rv = this.DoQueryExist("SELECT 1 FROM " + appSettingsTableName + " WHERE cfg_name='" + escapeSQL(name) + "';");
if (!rv)
{
return defaultValue;
}
return this.DoQuerySingle("SELECT cfg_value FROM " + appSettingsTableName + " WHERE cfg_name='" + escapeSQL(name) + "';");
}
public int GetIntConfig(string name, int defaultValue = 0)
{
string rv = this.GetConfig(name);
if (string.IsNullOrWhiteSpace(rv))
{
return defaultValue;
}
int n;
if (!int.TryParse(rv, out n))
{
n = defaultValue;
}
return n;
}
public bool GetBoolConfig(string name, bool defaultValue = false)
{
string rv = this.GetConfig(name);
if (string.IsNullOrWhiteSpace(rv))
{
return defaultValue;
}
if (rv.Equals("1"))
{
return true;
}
if (rv.Equals("true", StringComparison.CurrentCultureIgnoreCase))
{
return true;
}
return false;
}
protected bool create(string filename, bool overwriteFile, string password)
{
this.LastError = string.Empty;
if (File.Exists(filename))
{
if (overwriteFile)
{
try
{
File.Delete(filename);
}
catch (Exception exc)
{
this.LastError = exc.Message;
return false;
}
try
{
SQLiteConnection.CreateFile(filename);
}
catch (Exception exc)
{
this.LastError = exc.Message;
return false;
}
return this.LoadFile(filename, password);
}
else
{
return this.LoadFile(filename, password);
}
}
else
{
try
{
SQLiteConnection.CreateFile(filename);
}
catch (Exception exc)
{
this.LastError = exc.Message;
return false;
}
return this.LoadFile(filename, password);
}
}
protected string prepareQuery(string query, params string[] arguments)
{
string rv = query;
if (string.IsNullOrWhiteSpace(rv))
{
return string.Empty;
}
for (int i = 0; i < arguments.Length; i++)
{
rv = rv.Replace("[^" + (i + 1).ToString() + "]", escapeSQL(arguments[i]));
}
return rv;
}
protected string escapeSQL(string q) => q.Replace("'", "''").Trim();
protected string escapeValue(string text) => text.Replace("\"", "\\\"").Replace("\t", "\\t").Replace("\r", " \\r").Replace("\n", "\\n");
protected string encode64(string text) => Convert.ToBase64String(System.Text.Encoding.UTF8.GetBytes(text));
protected bool prepareAppSettings()
{
if (this.HasTable(appSettingsTableName))
{
return true;
}
int rv = this.DoNonQuery("CREATE TABLE " + appSettingsTableName + " (cfg_name TEXT, cfg_value TEXT)");
return rv > 0;
}
protected virtual bool prepareDatabase()
{
return true;
}
}
}