/// <summary>
/// 通过查询条件修改指定列
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="kvs">属性和值的键值对。用法 DbKvs.New().Add("属性名", 值)</param>
/// <param name="expression">查询条件，注意：不支持导航属性，如 "student => student.School.Id > 0" 将无法解析</param>
/// <returns>受影响的记录数</returns>
public int Update <T>(DbKvs kvs, Expression <Func <T, bool> > expression = null)
{
var entityInfo = MyEntityContainer.Get(typeof(T));
var setProperties = kvs.Where(kv => kv.Key != "Id").Select(kv => kv.Key);
var includeProperties = entityInfo.Properties.Where(p => setProperties.Contains(p.Name)).ToList();
if (includeProperties.Count == 0)
{
return(0);
}
string sql;
List <SqlParameter> parameters;
if (expression == null)
{
sql =
$"UPDATE [{entityInfo.TableName}] SET {string.Join(",", includeProperties.Select(p => $"{p.FieldName}=@{p.Name}"))} WHERE Id=@Id";
parameters = kvs.ToSqlParameters();
}
else
{
//var whereExpressionVisitor = new WhereExpressionVisitor<T>();
//whereExpressionVisitor.Visit(expression);
//var where = whereExpressionVisitor.GetCondition();
//var whereParameters = whereExpressionVisitor.GetParameters().ToSqlParameters();
var resolver = new ConditionResolver(entityInfo);
resolver.Resolve(expression.Body);
var where = resolver.GetCondition();
var whereParameters = resolver.GetParameters().ToSqlParameters();
parameters = kvs.ToSqlParameters();
parameters.AddRange(whereParameters);
where = string.IsNullOrWhiteSpace(where) ? "1=1" : where;
sql =
$"UPDATE [{entityInfo.TableName}] SET {string.Join(",", includeProperties.Select(p => $"{p.FieldName}=@{p.Name}"))} WHERE {where}";
}
using (var conn = new SqlConnection(_connectionString))
{
conn.Open();
var command = new SqlCommand(sql, conn);
command.Parameters.AddRange(parameters.ToArray());
return(command.ExecuteNonQuery());
}
}
public async Task <int> UpdateAsync <T>(int id, DbKvs kvs)
{
var entityInfo = MyEntityContainer.Get(typeof(T));
var setProperties = kvs.Where(kv => kv.Key != "Id").Select(kv => kv.Key);
var includeProperties = entityInfo.Properties.Where(p => setProperties.Contains(p.Name)).ToList();
if (includeProperties.Count == 0)
{
return(0);
}
var sql =
$"UPDATE [{entityInfo.TableName}] SET {string.Join(",", includeProperties.Select(p => $"{p.FieldName}=@{p.Name}"))} WHERE Id=@Id";
var parameters = kvs.ToSqlParameters();
parameters.Add(new SqlParameter("@Id", id));
using (var conn = new SqlConnection(_connectionString))
{
conn.Open();
var command = new SqlCommand(sql, conn);
command.Parameters.AddRange(parameters.ToArray());
return(await command.ExecuteNonQueryAsync());
}
}