/// <summary>
/// 拼接删除SQL语句
/// </summary>
/// <param name="entity">实体类</param>
/// <returns></returns>
public static StringBuilder DeleteSql <T>(T entity)
{
string tableName = DatabaseCommon.GetTableName <T>().ToString();
Type type = entity.GetType();
PropertyInfo[] props = type.GetProperties();
StringBuilder sb = new StringBuilder("Delete From " + tableName + " Where 1=1");
foreach (PropertyInfo prop in props)
{
if (prop.GetValue(entity, null) != null)
{
sb.Append(" AND " + prop.Name + " = " + DbHelper.DbParmChar + "" + prop.Name + "");
}
}
return(sb);
}
/// <summary>
/// 拼接 查询 SQL语句
/// </summary>
/// <param name="top">显示条数</param>
/// <returns></returns>
public static StringBuilder SelectSql <T>(int top) where T : new()
{
string tableName = DatabaseCommon.GetTableName <T>().ToString();
PropertyInfo[] props = GetProperties(new T().GetType());
StringBuilder sbColumns = new StringBuilder();
foreach (PropertyInfo prop in props)
{
sbColumns.Append(prop.Name + ",");
}
if (sbColumns.Length > 0)
{
sbColumns.Remove(sbColumns.ToString().Length - 1, 1);
}
string strSql = "SELECT top {0} {1} FROM {2} WHERE 1=1 ";
strSql = string.Format(strSql, top, sbColumns.ToString(), tableName + " ");
return(new StringBuilder(strSql));
}
/// <summary>
/// 泛型方法，反射生成UpdateSql语句
/// </summary>
/// <param name="entity">实体类</param>
/// <returns>int</returns>
public static StringBuilder UpdateSql <T>(T entity)
{
string tableName = DatabaseCommon.GetTableName <T>().ToString();
string pkName = GetKeyField <T>().ToString();
Type type = entity.GetType();
PropertyInfo[] props = type.GetProperties();
StringBuilder sb = new StringBuilder();
sb.Append("Update ");
sb.Append(tableName);
sb.Append(" Set ");
bool isFirstValue = true;
foreach (PropertyInfo prop in props)
{
if (prop.GetValue(entity, null) != null && pkName != prop.Name)
{
if (isFirstValue)
{
isFirstValue = false;
sb.Append(prop.Name);
sb.Append("=");
sb.Append(DbHelper.DbParmChar + prop.Name);
}
else
{
sb.Append("," + prop.Name);
sb.Append("=");
sb.Append(DbHelper.DbParmChar + prop.Name);
}
}
}
sb.Append(" Where ").Append(pkName).Append("=").Append(DbHelper.DbParmChar + pkName);
return(sb);
}
/// <summary>
/// 拼接 查询最大数 SQL语句
/// </summary>
/// <param name="propertyName">属性字段</param>
/// <returns></returns>
public static StringBuilder SelectMaxSql <T>(string propertyName) where T : new()
{
string tableName = DatabaseCommon.GetTableName <T>().ToString(); //获取表名
return(new StringBuilder("SELECT MAX(" + propertyName + ") FROM " + tableName + " WHERE 1=1 "));
}
/// <summary>
/// 拼接 查询条数 SQL语句
/// </summary>
/// <returns></returns>
public static StringBuilder SelectCountSql <T>() where T : new()
{
string tableName = DatabaseCommon.GetTableName <T>().ToString(); //获取表名
return(new StringBuilder("SELECT Count(1) FROM " + tableName + " WHERE 1=1 "));
}