protected string ConstructSelectStatement(out IEnumerable <KeyValuePair <string, object> > parameters,
Expression <Func <TEntity, bool> > expression = null,
Sort <TEntity, TKey> sorting = null)
{
var tableName = mapping.GetTableName <TEntity, TKey>();
var escapedTableName = mapping.GetEscapedTableName <TEntity, TKey>(dialectSettings);
var sqlBuilder = new StringBuilder();
parameters = null;
var fieldSet = string.Join(", ",
typeof(TEntity)
.GetTypeInfo()
.GetProperties(BindingFlags.Public | BindingFlags.Instance)
.Where(p => p.CanRead && p.PropertyType.IsSimpleType())
.Select(p => $"T_{tableName}.{mapping.GetEscapedColumnName<TEntity, TKey>(dialectSettings, p)} AS {tableName}_{mapping.GetColumnName<TEntity, TKey>(p)}"));
sqlBuilder.AppendLine($"SELECT {fieldSet} FROM {mapping.GetEscapedTableName<TEntity, TKey>(dialectSettings)} AS T_{tableName}");
if (expression != null)
{
var whereClauseBuildResult = new WhereClauseBuilder <TEntity, TKey>(mapping, dialectSettings, true).BuildWhereClause(expression);
sqlBuilder.AppendLine($"WHERE {whereClauseBuildResult.WhereClause} ");
parameters = new Dictionary <string, object>(whereClauseBuildResult.ParameterValues);
}
if (sorting != null && sorting.Count > 0)
{
sqlBuilder.Append("ORDER BY ");
sqlBuilder.Append(BuildOrderByClause(sorting));
}
return(sqlBuilder.ToString());
}
/// <summary>
/// Visits the children of <see cref="System.Linq.Expressions.MemberExpression"/>.
/// </summary>
/// <param name="node">The expression to visit.</param>
/// <returns>The modified expression, if it or any subexpression was modified; otherwise,
/// returns the original expression.</returns>
protected override Expression VisitMember(MemberExpression node)
{
if (node.Member.DeclaringType == typeof(TEntity) ||
typeof(TEntity).GetTypeInfo().IsSubclassOf(node.Member.DeclaringType))
{
var mappedFieldName = "";
if (this.useTableAlias)
{
mappedFieldName = $"T_{storeMapping.GetTableName<TEntity, TKey>()}.{storeMapping.GetEscapedColumnName<TEntity, TKey>(this.dialectSettings, node.Member.Name)}";
}
else
{
mappedFieldName = $"{storeMapping.GetEscapedTableName<TEntity, TKey>(dialectSettings)}.{storeMapping.GetEscapedColumnName<TEntity, TKey>(this.dialectSettings, node.Member.Name)}";
}
Out(mappedFieldName);
}
else
{
if (node.Member is FieldInfo)
{
ConstantExpression ce = node.Expression as ConstantExpression;
FieldInfo fi = node.Member as FieldInfo;
object fieldValue = fi.GetValue(ce.Value);
Expression constantExpr = Expression.Constant(fieldValue);
Visit(constantExpr);
}
else if (node.Member is PropertyInfo)
{
if (node.NodeType == ExpressionType.Constant)
{
ConstantExpression ce = node.Expression as ConstantExpression;
PropertyInfo pi = node.Member as PropertyInfo;
object fieldValue = pi.GetValue(ce.Value);
Expression constantExpr = Expression.Constant(fieldValue);
Visit(constantExpr);
}
else if (node.NodeType == ExpressionType.MemberAccess)
{
var memberExpression = node.Expression as MemberExpression;
VisitMember(memberExpression);
}
}
else
{
throw new NotSupportedException();
}
}
return(node);
}