I was migrating traditional JPA based project to reactive Project, which was based on r2dbc.
There have many dynamics SQL conjecture in our project before, like if user pass parameter exchange value as CME，we will add "and exchange='CME'" at the end of SQL and run it by JDBCTemplate:
List<Object> parameters = new ArrayList<>();
String sql = QUERY_BrokerIDs_Old;
sql += " and exchange = ?";
parameters.add(exchange);
if (!StringUtils.isEmpty(filter)) {
sql += " and memberID like ?";
parameters.add("%" + filter.trim().toUpperCase() + "%");
}
sql += " order by id";
if (page > 0 && pageSize > 0) {
int offset = (page - 1) * pageSize;
String pageClause = PAGE_CLAUSE;
sql += pageClause;
parameters.add(offset);
parameters.add(pageSize);
}
return jdbcTemplate.queryForList(sql, parameters.toArray(), String.class);
I found r2dbc repository provide multiple convient methods, like findAll, getXxxByXxx,I really like it. And we also can declare the SQL in #Query like:
#Query("SELECT * FROM person WHERE lastname = :lastname")
Flux<Person> findByLastname(String lastname);
But does it support dynamic parameter as query conditions in its repository class? Or I can do some customize on it to implement it?
Otherwise I only can implement it by SQL conjecture and run it by template， like the old way before…
Related
I want to build a SELECT statement using a list of conditions that come from the query string of a REST api. I wrote this function, but maybe it is vulnerable to SQL injection. Can someone tell me if this is vulnerable how to fix it? Perhaps I should use some kind of SQLBuilder package? or is there a way to do it with just dotNet. I'm using dotNet 4.6.1
string BuildSelect(NameValueCollection query)
{
var result = "SELECT * FROM MYTABLE";
if (query.Count == 0) return result;
var logic = " WHERE ";
foreach (string key in query)
foreach (string v in query.GetValues(key))
{
result += logic + key + " = " + v;
logic = " AND ";
}
return result;
}
Yes it is vulnerable to SQL injection attack. You could build your query to use parameters instead (you are simply using an = check only).
Since you know the tablename, that means you also know what the columns (keys) can be. Thus, you could loop your columns, if the collection has that key then add it to the where as a parameterized statement BUT value part is NOT passed as a string, you parse it to the type it should be (or let the backend do the conversion and get error if cannot be converted). In pseudocode:
List<string> clauses = new List<string>();
var result = "SELECT * FROM MYTABLE";
foreach( var col in myTable.Columns )
{
if (query.ContainsKey(col.Name))
{
clauses.Add( $"{col.Name} = #{col.Name}";
string v = query[col.Name];
command.Parameters.Add( $"#{col.Name}", col.Type).Value = typeParse(v);
}
}
if (clauses.Any())
{
result += " WHERE " + string.Join( " AND ", clauses );
}
return result;
HTH
I need to write this in NHibernate Criteria as a projection:
The subAlias is _not_ the root alias, so {alias} cannot replace the correct sql alias, and my problem is that other parts of the query makes the subAlias vary in the generated sql
ROUND(alias.Property / parameterValueFromMethodParameter + ", 0)
* parameterValueFromMethodParameter2 AS SQLAlias
This is how far (off) I got:
.Add(Projections.SqlFunction(new VarArgsSQLFunction("(", "/", ")")
, NHibernateUtil.Int32
, Projections.SqlFunction("round"
, NHibernateUtil.Decimal
, Projections.Property("subAlias.Property"))), "SQLAlias"))
This produces the following SQL code:
ROUND( subAlias3(4).Property
)AS y1_
Does anyone have experience with projections like this?
I found this patch i hibernate, but seems like it was not implemented.
If I understand your example properly, the most easy solution would be to use SQL projection:
// the parameterValueFromMethodParameter
// and parameterValueFromMethodParameter2
var computationParams = new object[] {2, 4}; // just an example numbers
// SQL To be generated
// see that here we work with COLUMN name, not property
var sqlSnippet = " ( ROUND({{alias}}.ColumnName / {0}, 0) * {1} ) AS computed ";
// put that all together
var projectSql = string.Format(sqlSnippet, computationParams);
// IProjection
var projection = Projections.SqlProjection(projectSql, new string[0], new IType[0]);
// add it to SELECT clause
criteria.SetProjection(Projections.ProjectionList()
.Add(projection)
...
);
That should work...
I Solved it by writing my own SQL IProjection. With a litte help from this example.
public SqlString ToSqlString(ICriteria criteria, int loc, ICriteriaQuery criteriaQuery, IDictionary<string, IFilter> enabledFilters)
{
string replacedString = Regex.Replace(
this.sql,
#"{([a-zA-Z_]((\.)?[a-zA-Z0-9_])*)}",
m =>
{
ICriteria critter = criteria.GetCriteriaByAlias(m.Groups[1].Value);
if (critter != null)
{
return criteriaQuery.GetSQLAlias(critter);
}
return m.Groups[0].Value;
});
return new SqlString(replacedString);
}
So now I can do (In a SqlGroupProjection):
ROUND({subAlias}.XCoord / " + aggregationSize + ", 0) * " + aggregationSize + " AS SQLAlias
There are some other attempts on extending (N)Hibernate to handle this alias in raw SQL problem:
Expression.Sql should support aliases other than {alias}
Support for referencing non-root entities in Criteria SQL expressions
I've read Give me Parameterized SQL or give me death numerous times.
The advantage of Parameterized SQL for Strings, Dates, and floating-point numbers is very obvious and indisputable.
My question is: what about ints?
I ask because, oftentimes, if I'm writing a query or update and the only parameter is an int, I'll just write an inline sql and append the int as a shortcut ("select * from table where id = " + id).
My question: Are there any advantages to using Parameterized SQL for ints alone?
To illustrate with Java:
Are there any advantage to this:
Connection conn;
int id;
String sql = "select * from table where id = ?";
try (PreparedStatement p_stmt = conn.prepareStatement(sql)) {
p_stmt.setInt(1, id);
ResultSet results = p_stmt.executeQuery();
// ...
} catch (SQLException e) {
// ...
}
over this:
Connection conn;
int id;
String sql = "select * from table where id = " + id;
try (Statement stmt = conn.createStatement()) {
ResultSet results = stmt.executeQuery(sql);
// ...
} catch (SQLException e) {
// ...
}
I would say the biggest advantage would be consistency. If you decide that all SQL built by string concatenation is "wrong", it's easier to verify that your code is "right", compared to a rule like "All SQL built by string concatenation is wrong, except that which deals with ints as parameters".
Another case, say: down the line, you want to introduce sorting or grouping to the query, suddenly, your line turns into something like this:
String sql = "select * from table where id = " + id + " order by somecolumn";
And hopefully you remembered the space before order. And that everyone after you does also.
There is much to be said for doing things only one way, especially when that one way is the right thing most of the time.
Using Dapper-dot-net...
The following yields no results in the data object:
var data = conn.Query(#"
select top 25
Term as Label,
Type,
ID
from SearchTerms
WHERE Term like '%#T%'",
new { T = (string)term });
However, when I just use a regular String Format like:
string QueryString = String.Format("select top 25 Term as Label, Type, ID from SearchTerms WHERE Term like '%{0}%'", term);
var data = conn.Query(QueryString);
I get 25 rows back in the collection. Is Dapper not correctly parsing the end of the parameter #T?
Try:
term = "whateverterm";
var encodeForLike = term => term.Replace("[", "[[]").Replace("%", "[%]");
string term = "%" + encodeForLike(term) + "%";
var data = conn.Query(#"
select top 25
Term as Label,
Type,
ID
from SearchTerms
WHERE Term like #term",
new { term });
There is nothing special about like operators, you never want your params inside string literals, they will not work, instead they will be interpreted as a string.
note
The hard-coded example in your second snippet is strongly discouraged, besides being a huge problem with sql injection, it can cause dapper to leak.
caveat
Any like match that is leading with a wildcard is not SARGable, which means it is slow and will require an index scan.
Yes it does. This simple solution has worked for me everytime:
db.Query<Remitente>("SELECT *
FROM Remitentes
WHERE Nombre LIKE #n", new { n = "%" + nombre + "%" })
.ToList();
Best way to use this to add concat function in query as it save in sql injecting as well, but concat function is only support above than sql 2012
string query = "SELECT * from country WHERE Name LIKE CONCAT('%',#name,'%');"
var results = connection.query<country>(query, new {name});
The answer from Sam wasn't working for me so after some testing I came up with using the SQLite CONCAT equivalent which seems to work:
string sql = "SELECT * FROM myTable WHERE Name LIKE '%' || #NAME || '%'";
var data = IEnumerable data = conn.Query(sql, new { NAME = Name });
Just to digress on Sam's answer, here is how I created two helper methods to make searches a bit easier using the LIKE operator.
First, creating a method for generating a parameterized query, this method uses dynamic: , but creating a strongly typed generic method should be more desired in many cases where you want static typing instead of dynamic.
public static dynamic ParameterizedQuery(this IDbConnection connection, string sql, Dictionary<string, object> parametersDictionary)
{
if (string.IsNullOrEmpty(sql))
{
return null;
}
string missingParameters = string.Empty;
foreach (var item in parametersDictionary)
{
if (!sql.Contains(item.Key))
{
missingParameters += $"Missing parameter: {item.Key}";
}
}
if (!string.IsNullOrEmpty(missingParameters))
{
throw new ArgumentException($"Parameterized query failed. {missingParameters}");
}
var parameters = new DynamicParameters(parametersDictionary);
return connection.Query(sql, parameters);
}
Then adding a method to create a Like search term that will work with Dapper.
public static string Like(string searchTerm)
{
if (string.IsNullOrEmpty(searchTerm))
{
return null;
}
Func<string, string> encodeForLike = searchTerm => searchTerm.Replace("[", "[[]").Replace("%", "[%]");
return $"%{encodeForLike(searchTerm)}%";
}
Example usage:
var sql = $"select * from products where ProductName like #ProdName";
var herringsInNorthwindDb = connection.ParameterizedQuery(sql, new Dictionary<string, object> { { "#ProdName", Like("sild") } });
foreach (var herring in herringsInNorthwindDb)
{
Console.WriteLine($"{herring.ProductName}");
}
And we get our sample data from Northwind DB:
I like this approach, since we get helper extension methods to do repetitive work.
My solution simple to this problem :
parameter.Add("#nomeCliente", dfNomeCliPesquisa.Text.ToUpper());
query = "SELECT * FROM cadastrocliente WHERE upper(nome) LIKE " + "'%" + dfNomeCliPesquisa.Text.ToUpper() + "%'";
I am trying to search an XML field within a table, This is not supported with EF.
Without using pure Ado.net is possible to have native SQL support with EF?
For .NET Framework version 4 and above: use ObjectContext.ExecuteStoreCommand() if your query returns no results, and use ObjectContext.ExecuteStoreQuery if your query returns results.
For previous .NET Framework versions, here's a sample illustrating what to do. Replace ExecuteNonQuery() as needed if your query returns results.
static void ExecuteSql(ObjectContext c, string sql)
{
var entityConnection = (System.Data.EntityClient.EntityConnection)c.Connection;
DbConnection conn = entityConnection.StoreConnection;
ConnectionState initialState = conn.State;
try
{
if (initialState != ConnectionState.Open)
conn.Open(); // open connection if not already open
using (DbCommand cmd = conn.CreateCommand())
{
cmd.CommandText = sql;
cmd.ExecuteNonQuery();
}
}
finally
{
if (initialState != ConnectionState.Open)
conn.Close(); // only close connection if not initially open
}
}
Using Entity Framework 5.0 you can use ExecuteSqlCommand to execute multi-line/multi-command pure SQL statements. This way you won't need to provide any backing object to store the returned value since the method returns an int (the result returned by the database after executing the command).
Sample:
context.Database.ExecuteSqlCommand(#
"-- Script Date: 10/1/2012 3:34 PM - Generated by ExportSqlCe version 3.5.2.18
SET IDENTITY_INSERT [Students] ON;
INSERT INTO [Students] ([StudentId],[FirstName],[LastName],[BirthDate],[Address],[Neighborhood],[City],[State],[Phone],[MobilePhone],[Email],[Enrollment],[Gender],[Status]) VALUES (12,N'First Name',N'SecondName',{ts '1988-03-02 00:00:00.000'},N'RUA 19 A, 60',N'MORADA DO VALE',N'BARRA DO PIRAÍ',N'Rio de Janeiro',N'3346-7125',NULL,NULL,{ts '2011-06-04 21:25:26.000'},2,1);
INSERT INTO [Students] ([StudentId],[FirstName],[LastName],[BirthDate],[Address],[Neighborhood],[City],[State],[Phone],[MobilePhone],[Email],[Enrollment],[Gender],[Status]) VALUES (13,N'FirstName',N'LastName',{ts '1976-04-12 00:00:00.000'},N'RUA 201, 2231',N'RECANTO FELIZ',N'BARRA DO PIRAÍ',N'Rio de Janeiro',N'3341-6892',NULL,NULL,{ts '2011-06-04 21:38:38.000'},2,1);
");
For more on this, take a look here: Entity Framework Code First: Executing SQL files on database creation
For Entity Framework 5 use context.Database.SqlQuery.
And for Entity Framework 4 use context.ExecuteStoreQuery
the following code:
public string BuyerSequenceNumberMax(int buyerId)
{
string sequenceMaxQuery = "SELECT TOP(1) btitosal.BuyerSequenceNumber FROM BuyerTakenItemToSale btitosal " +
"WHERE btitosal.BuyerID = " + buyerId +
"ORDER BY CONVERT(INT,SUBSTRING(btitosal.BuyerSequenceNumber,7, LEN(btitosal.BuyerSequenceNumber))) DESC";
var sequenceQueryResult = context.Database.SqlQuery<string>(sequenceMaxQuery).FirstOrDefault();
string buyerSequenceNumber = string.Empty;
if (sequenceQueryResult != null)
{
buyerSequenceNumber = sequenceQueryResult.ToString();
}
return buyerSequenceNumber;
}
To return a List use the following code:
public List<PanelSerialList> PanelSerialByLocationAndStock(string locationCode, byte storeLocation, string itemCategory, string itemCapacity, byte agreementType, string packageCode)
{
string panelSerialByLocationAndStockQuery = "SELECT isws.ItemSerialNo, im.ItemModel " +
"FROM Inv_ItemMaster im " +
"INNER JOIN " +
"Inv_ItemStockWithSerialNoByLocation isws " +
" ON im.ItemCode = isws.ItemCode " +
" WHERE isws.LocationCode = '" + locationCode + "' AND " +
" isws.StoreLocation = " + storeLocation + " AND " +
" isws.IsAvailableInStore = 1 AND " +
" im.ItemCapacity = '" + itemCapacity + "' AND " +
" isws.ItemSerialNo NOT IN ( " +
" Select sp.PanelSerialNo From Special_SpecialPackagePriceForResale sp " +
" Where sp.PackageCode = '" + packageCode + "' )";
return context.Database.SqlQuery<PanelSerialList>(panelSerialByLocationAndStockQuery).ToList();
}
Keep it simple
using (var context = new MyDBEntities())
{
var m = context.ExecuteStoreQuery<MyDataObject>("Select * from Person", string.Empty);
//Do anything you wonna do with
MessageBox.Show(m.Count().ToString());
}
public class RaptorRepository<T>
where T : class
{
public RaptorRepository()
: this(new RaptorCoreEntities())
{
}
public RaptorRepository(ObjectContext repositoryContext)
{
_repositoryContext = repositoryContext ?? new RaptorCoreEntities();
_objectSet = repositoryContext.CreateObjectSet<T>();
}
private ObjectContext _repositoryContext;
private ObjectSet<T> _objectSet;
public ObjectSet<T> ObjectSet
{
get
{
return _objectSet;
}
}
public void DeleteAll()
{
_repositoryContext
.ExecuteStoreCommand("DELETE " + _objectSet.EntitySet.ElementType.Name);
}
}
So what do we say about all this in 2017? 80k consultations suggests that running a SQL request in EF is something a lot of folk want to do. But why? For what benefit?
Justin, a guru with 20 times my reputation, in the accepted answer gives us a static method that looks line for line like the equivalent ADO code. Be sure to copy it well because there are a few subtleties to not get wrong. And you're obliged to concatenate your query with your runtime parameters since there's no provision for proper parameters. So all users of this method will be constructing their SQL with string methods (fragile, untestable, sql injection), and none of them will be unit testing.
The other answers have the same faults, only moreso. SQL buried in double quotes. SQL injection opportunities liberally scattered around. Esteemed peers, this is absolutely savage behaviour. If this was C# being generated, there would be a flame war. We don't even accept generating HTML this way, but somehow its OK for SQL. I know that query parameters were not the subject of the question, but we copy and reuse what we see, and the answers here are both models and testaments to what folk are doing.
Has EF melted our brains? EF doesn't want you to use SQL, so why use EF to do SQL.
Wanting to use SQL to talk to a relational DB is a healthy, normal impulse in adults. QueryFirst shows how this could be done intelligently, your sql in .sql file, validated as you type, with intellisense for tables and columns. The C# wrapper is generated by the tool, so your queries become discoverable in code, with intellisense for your inputs and results. End to end strong typing, without ever having to worry about a type. No need to ever remember a column name, or its index. And there are numerous other benefits... The temptation to concatenate is removed. The possibility of mishandling your connections also. All your queries and the code that accesses them are continuously integration-tested against your dev DB. Schema changes in your DB pop up as compile errors in your app. We even generate a self test method in the wrapper, so you can test new versions of your app against existing production databases, rather than waiting for the phone to ring. Anyone still need convincing?
Disclaimer: I wrote QueryFirst :-)