C SQLite class library

String rotation Datetime Mining pit
1. Note the date format saved to the database DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss")
If the format is not uniform, the search will be inaccurate .
2. Table design recommendations sqlitestudio Tools

using System;using System.Collections.Generic;using System.Text;namespace System.Data.SQLite{    public class SQLiteColumn    {        public string ColumnName = "";        public bool PrimaryKey = false;        public ColType ColDataType = ColType.Text;        public bool AutoIncrement = false;        public bool NotNull = false;        public string DefaultValue = "";        public SQLiteColumn()        { }        public SQLiteColumn(string colName)        {            ColumnName = colName;            PrimaryKey = false;            ColDataType = ColType.Text;            AutoIncrement = false;        }        public SQLiteColumn(string colName, ColType colDataType)        {            ColumnName = colName;            PrimaryKey = false;            ColDataType = colDataType;            AutoIncrement = false;        }        public SQLiteColumn(string colName, bool autoIncrement)        {            ColumnName = colName;            if (autoIncrement)            {                PrimaryKey = true;                ColDataType = ColType.Integer;                AutoIncrement = true;            }            else            {                PrimaryKey = false;                ColDataType = ColType.Text;                AutoIncrement = false;            }        }        public SQLiteColumn(string colName, ColType colDataType, bool primaryKey, bool autoIncrement, bool notNull, string defaultValue)        {            ColumnName = colName;            if (autoIncrement)            {                PrimaryKey = true;                ColDataType = ColType.Integer;                AutoIncrement = true;            }            else            {                PrimaryKey = primaryKey;                ColDataType = colDataType;                AutoIncrement = false;                NotNull = notNull;                DefaultValue = defaultValue;            }        }    }}

using System;using System.Collections.Generic;using System.Text;namespace System.Data.SQLite{    public class SQLiteColumnList : IList<SQLiteColumn>    {        List<SQLiteColumn> _lst = new List<SQLiteColumn>();        private void CheckColumnName(string colName)        {            for (int i = 0; i < _lst.Count; i++)            {                if (_lst[i].ColumnName == colName)                    throw new Exception("Column name of \"" + colName + "\" is already existed.");            }        }        public int IndexOf(SQLiteColumn item)        {            return _lst.IndexOf(item);        }        public void Insert(int index, SQLiteColumn item)        {            CheckColumnName(item.ColumnName);            _lst.Insert(index, item);        }        public void RemoveAt(int index)        {            _lst.RemoveAt(index);        }        public SQLiteColumn this[int index]        {            get            {                return _lst[index];            }            set            {                if (_lst[index].ColumnName != value.ColumnName)                {                    CheckColumnName(value.ColumnName);                }                _lst[index] = value;            }        }        public void Add(SQLiteColumn item)        {            CheckColumnName(item.ColumnName);            _lst.Add(item);        }        public void Clear()        {            _lst.Clear();        }        public bool Contains(SQLiteColumn item)        {            return _lst.Contains(item);        }        public void CopyTo(SQLiteColumn[] array, int arrayIndex)        {            _lst.CopyTo(array, arrayIndex);        }        public int Count        {            get { return _lst.Count; }        }        public bool IsReadOnly        {            get { return false; }        }        public bool Remove(SQLiteColumn item)        {            return _lst.Remove(item);        }        public IEnumerator<SQLiteColumn> GetEnumerator()        {            return _lst.GetEnumerator();        }        Collections.IEnumerator Collections.IEnumerable.GetEnumerator()        {            return _lst.GetEnumerator();        }    }}

using System;using System.Collections.Generic;using System.Text;namespace System.Data.SQLite{    public class SQLiteTable    {        public string TableName = "";        public SQLiteColumnList Columns = new SQLiteColumnList();        public SQLiteTable()        { }        public SQLiteTable(string name)        {            TableName = name;        }    }}

using System;using System.Collections.Generic;using System.Text;using System.Data;using System.Globalization;using System.IO;namespace System.Data.SQLite{    public enum ColType    {        Text,        DateTime,        Integer,        Decimal,        BLOB    }    public class SQLiteHelper    {        public static string ConnectionString = " route ";        public string Error = "";        /// <summary>        ///  Create database         /// </summary>        public bool CreateDataBase()        {            string path = Path.GetDirectoryName(ConnectionString.Replace("data source=", ""));            if ((!string.IsNullOrWhiteSpace(path)) && (!Directory.Exists(path)))            {                Directory.CreateDirectory(path);            }            if (!File.Exists(ConnectionString))            {                SQLiteConnection.CreateFile(ConnectionString);            }            return true;        }        // Create table code :        //SQLiteTable tb = new SQLiteTable("person");        //tb.Columns.Add(new SQLiteColumn("id", true));        //tb.Columns.Add(new SQLiteColumn("name"));        //tb.Columns.Add(new SQLiteColumn("membershipid", ColType.Integer));        //tb.Columns.Add(new SQLiteColumn("level", ColType.Decimal, false, false, "5.5"));        //sh.CreateTable(tb);        /// <summary>        ///  Create table         /// </summary>        /// <param name="table"></param>        /// <returns></returns>        public bool CreateTable(SQLiteTable table)        {            StringBuilder sb = new Text.StringBuilder();            sb.Append("create table if not exists `");            sb.Append(table.TableName);            sb.AppendLine("`(");            bool firstRecord = true;            foreach (SQLiteColumn col in table.Columns)            {                if (col.ColumnName.Trim().Length == 0)                {                    throw new Exception("Column name cannot be blank.");                }                if (firstRecord)                    firstRecord = false;                else                    sb.AppendLine(",");                sb.Append(col.ColumnName);                sb.Append(" ");                if (col.AutoIncrement)                {                    sb.Append("integer primary key autoincrement");                    continue;                }                switch (col.ColDataType)                {                    case ColType.Text:                        sb.Append("text"); break;                    case ColType.Integer:                        sb.Append("integer"); break;                    case ColType.Decimal:                        sb.Append("decimal"); break;                    case ColType.DateTime:                        sb.Append("datetime"); break;                    case ColType.BLOB:                        sb.Append("blob"); break;                }                if (col.PrimaryKey)                    sb.Append(" primary key");                else if (col.NotNull)                    sb.Append(" not null");                else if (col.DefaultValue.Length > 0)                {                    sb.Append(" default ");                    if (col.DefaultValue.Contains(" ") || col.ColDataType == ColType.Text || col.ColDataType == ColType.DateTime)                    {                        sb.Append("'");                        sb.Append(col.DefaultValue);                        sb.Append("'");                    }                    else                    {                        sb.Append(col.DefaultValue);                    }                }            }            sb.AppendLine(");");            try            {                using (SQLiteConnection conn = new SQLiteConnection(ConnectionString))                {                    conn.Open();                    SQLiteCommand comm = new SQLiteCommand();                    comm.Connection = conn;                    comm.CommandText = sb.ToString();                    comm.CommandType = CommandType.Text;                    comm.CommandTimeout = conn.ConnectionTimeout;                    comm.ExecuteNonQuery();                    conn.Close();                }                return true;            }            catch (Exception ex)            {                Error = " System failure :GetDataSetBySQLString," + ex.ToString();                return false;            }        }        /// <summary>        ///  Query data         /// </summary>        public DataTable GetDataTableBySql(string sql)        {            return GetDataSetBySQLString(sql).Tables[0];        }        public DataSet GetDataSetBySQLString(string SQLString)        {            try            {                using (SQLiteConnection conn = new SQLiteConnection(ConnectionString))                {                    conn.Open();                    SQLiteCommand comm = new SQLiteCommand();                    comm.Connection = conn;                    comm.CommandText = SQLString;                    comm.CommandType = CommandType.Text;                    comm.CommandTimeout = conn.ConnectionTimeout;                    DataSet ds = new DataSet("SQLDataSet");                    SQLiteDataAdapter adapter = new SQLiteDataAdapter();                    adapter.SelectCommand = comm;                    adapter.Fill(ds, "SQLDataSet");                    conn.Close();                    return ds;                }            }            catch (Exception ex)            {                Error = " System failure :GetDataSetBySQLString," + ex.ToString();                return null;            }        }        /// <summary>        ///  Add or update data         /// </summary>        public int UpdateBySQL(string sql)        {            using (SQLiteConnection con = new SQLiteConnection(ConnectionString))            {                con.Open();                SQLiteCommand cmd = null;                try                {                    cmd = new SQLiteCommand(sql, con);                    object objResult = cmd.ExecuteScalar();                    con.Close();                    if (objResult == null)                    {                        return 0;                    }                    else                    {                        return 1;                    }                }                catch (Exception ex)                {                    Error = ex.ToString();                    con.Close();                    Error = " System failure :UpdateBySQL," + ex.ToString();                    return -1;                }            }        }        /// <summary>        ///  Delete database data         /// </summary>        public int DeltetBySQL(string sql)        {            using (SQLiteConnection con = new SQLiteConnection(ConnectionString))            {                con.Open();                SQLiteCommand cmd = null;                try                {                    cmd = new SQLiteCommand(sql, con);                    int objResult = cmd.ExecuteNonQuery();                    con.Close();                    return 0;                }                catch (Exception ex)                {                    Error = ex.ToString();                    con.Close();                    Error = " System failure :DeltetBySQL," + ex.ToString();                    return -1;                }            }        }    }}

Calling method
SQLiteHelper.ConnectionString ="data source=F:\db\Db_Phone";
// Create database
SQLiteHelper sh = new SQLiteHelper();
// Create table
SQLiteTable tb = new SQLiteTable("person");
tb.Columns.Add(new SQLiteColumn("id", true));
tb.Columns.Add(new SQLiteColumn("name"));
tb.Columns.Add(new SQLiteColumn("membershipid", ColType.Integer));
tb.Columns.Add(new SQLiteColumn("level", ColType.Decimal, false, false, "5.5"));
sh.CreateTable(tb);
// Call statement
string sql = string.Format("INSERT INTO PicFiles (SN,Path,Createdate) VALUES ('{0}','{1}','{2}')", "fan", "wen", DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss"));
int rel = sh.UpdateBySQL(sql);
author ：fanwenhu

Game programming , A game development favorite ~

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