/// <summary>
/// Builds the WHERE clause from the given expression object.
/// </summary>
/// <param name="expression">The expression object.</param>
/// <returns>The <c>Apworks.Storage.Builders.WhereClauseBuildResult</c> instance
/// which contains the build result.</returns>
public WhereClauseBuildResult BuildWhereClause(Expression <Func <TEntity, bool> > expression)
{
this.sb.Clear();
this.parameterValues.Clear();
this.Visit(expression.Body);
WhereClauseBuildResult result = new WhereClauseBuildResult
{
ParameterValues = parameterValues,
WhereClause = sb.ToString()
};
return(result);
}
protected Tuple <string, IEnumerable <Tuple <string, string, object> >, WhereClauseBuildResult> ConstructUpdateStatement(TEntity entity,
Expression <Func <TEntity, bool> > expression,
IEnumerable <Expression <Func <TEntity, object> > > updateFields)
{
var sqlBuilder = new StringBuilder($"UPDATE {mapping.GetEscapedTableName<TEntity, TKey>(dialectSettings)} SET ");
var columnNames = new List <Tuple <string, string, object> >();
var updateProperties = typeof(TEntity)
.GetTypeInfo()
.GetProperties(BindingFlags.Public | BindingFlags.Instance)
.Where(p => p.CanRead && p.PropertyType.IsSimpleType());
if (updateFields != null)
{
updateProperties = updateProperties.Where(p =>
updateFields.Any(expr => ((MemberExpression)StripConvert(expr).Body).Member.Name == p.Name));
}
updateProperties
.ToList()
.ForEach(ps =>
{
columnNames.Add(new Tuple <string, string, object>(mapping.GetEscapedColumnName <TEntity, TKey>(dialectSettings, ps),
$"{this.dialectSettings.ParameterChar}{ps.Name}", ps.GetValue(entity) ?? DBNull.Value));
});
for (var i = 0; i < columnNames.Count; i++)
{
sqlBuilder.Append($"{columnNames[i].Item1}={columnNames[i].Item2}");
if (i < columnNames.Count - 1)
{
sqlBuilder.Append(", ");
}
}
WhereClauseBuildResult whereClauseBuildResult = null;
if (expression != null)
{
whereClauseBuildResult = this.BuildWhereClause(expression);
sqlBuilder.Append($" WHERE {whereClauseBuildResult.WhereClause}");
}
return(new Tuple <string, IEnumerable <Tuple <string, string, object> >, WhereClauseBuildResult>(sqlBuilder.ToString(),
columnNames,
whereClauseBuildResult));
}
