There is a procedure in %Dictionary.ClassDefinitionQuery which lists a class summary; in Java I call it like this:
public void readClasses(final Path dir)
throws SQLException
{
final String call
= "{ call %Dictionary.ClassDefinitionQuery_Summary() }";
try (
final CallableStatement statement = connection.prepareCall(call);
final ResultSet rs = statement.executeQuery();
) {
String className;
int count = 0;
while (rs.next()) {
// Skip if System is not 0
if (rs.getInt(5) != 0)
continue;
className = rs.getString(1);
// Also skip if the name starts with a %
if (className.charAt(0) == '%')
continue;
//System.out.println(className);
count++;
}
System.out.println("read: " + count);
}
}
In namespace SAMPLES this returns 491 rows.
I try and replicate it with a pure SQL query like this:
private void listClasses(final Path dir)
throws SQLException
{
final String query = "select id, super"
+ " from %Dictionary.ClassDefinition"
+ " where System = '0' and name not like '\\%%' escape '\\'";
try (
final PreparedStatement statement
= connection.prepareStatement(query);
final ResultSet rs = statement.executeQuery();
) {
int count = 0;
while (rs.next()) {
//System.out.println(rs.getString(1) + ';' + rs.getString(2));
count++;
}
System.out.println("list: " + count);
}
}
Yet when running the program I get this:
list: 555
read: 491
Why are the results different?
I have looked at the code of %Dictionary.ClassDefinitionQuery but I don't understand why it gives different results... All I know, if I store the names in sets and compare, is that:
nothing is missing from list that is in read;
most, but not all, classes returned by list which are not in read are CSP pages.
But that's it.
How I can I replicate the behaviour of the summary procedure in SQL?
Different is in one property. %Dictionary.ClassDefinitionQuery_Summary shows only classes with Deployed<>2. So, sql must be such.
select id,super from %Dictionary.ClassDefinition where deployed <> 2
But one more things is, why count may be different is, such sql requests may be compilled to temporary class, for example "%sqlcq.SAMPLES.cls22"
Related
I want to check the username and password with sqlite table,In my case query always returns false...
This is my Query...
public boolean validateUser(String u_name, String p_word){
Cursor c = getReadableDatabase().rawQuery(
"SELECT FNAME,PASSWORD FROM " + TABLE_NAME + " WHERE "
+ fname + "='" + u_name+"'AND "+ password +"='"+ p_word+"'" , null);
if (c!=null)
{
return true;
}
else{
return false;
}
}
Checking whether or not the Cursor is null is basically useless as a valid Cursor will be returned by rawQuery. That is no data to extract will result in an empty Cursor with no rows, whilst if data has been extracted the Cursor will have 1 or more rows.
You should check whether or not the Cursor is empty by using the Cursor getCount() method which will return 0 if there are no rows or the number of rows. Alternately you could use some of the Cursor's move methods which will return true/false depending upon whether the move can be performed. e.g if (c.moveToFirst) { ... //row(s) exist} else { ... //no rows exists }.
You should also close the Cursor before returning. So perhaps use :-
public boolean validateUser(String u_name, String p_word){
Cursor c = getReadableDatabase().rawQuery(
"SELECT FNAME,PASSWORD FROM " + TABLE_NAME + " WHERE "
+ fname + "='" + u_name+"'AND "+ password +"='"+ p_word+"'" , null);
int count = c.getCount(); // get the number of rows
c.close(); // Close the Cursor
return count > 0; // return result (no data found = false, else true)
Many would recommend not using rawQuery but rather the convenience Cursor query method. This could be :-
public boolean validateUser(String u_name, String p_word) {
String[] columns = new String[]{
FNAME,
PASSWORD
};
String whereclause = FNAME + "=? AND " + PASSWORD + "=?";
String[] whereargs = new String[]{
u_name,
p_word
};
Cursor c = this.getWritableDatabase().query(
TABLE_NAME,
columns,
whereclause,
whereargs,
null,null,null
);
int count = c.getCount();
c.close();
return count > 0;
}
Note the above code is in-principle code and hasn't been tested so it may contain typing errors.
The above code assumes that the method is within the Database Helper class (i.e. a subclass of SQLiteOpenHelper).
The assumption has been made that FNAME and PASSWORD are the correct String variables to be used for the column names as opposed to fname and password
Assumptions have been made due to the limited code made available.
I am using Npgsql for postgresql in C++/CLI. So, the problem is, I have a db on my computer, and I am trying to select some of data from it's "movies" table. I already entered some data inside it, so I know that it has some data. But when I try to select some of them, answer to my query is empty. My code is like below:
public: string* SelectData(string* torrent)
{
conn->Open();
String ^ query = "SELECT title, director, actors, genre FROM movies";
Npgsql::NpgsqlCommand ^ command = gcnew NpgsqlCommand(query, conn);
try{
Npgsql::NpgsqlDataReader ^ dr = command->ExecuteReader();
for (int i = 0; i < N_TORRENT; i++)
{
if(dr->Read())
{
string std1 = toStandardString((String^)dr[0]);
string std2 = toStandardString((String^)dr[1]);
string std3 = toStandardString((String^)dr[2]);
string std4 = toStandardString((String^)dr[3]);
torrent[i] = std1 + " " + std2 + " " + std3 + " " + std4;
}
}
return torrent;
}
finally{
conn->Close();
}
}
(For the ones who will look for this question's answer)
Problem solved when I changed my query and look for the "title" column that are not empty. But this is ridiculus, so I beleive the problem was about pgAdmin. Because my insert query was not working either, but I added "rowseffected" variable and it shows the effected row's number and looks like it is working. So the problem is probably about the pgAdmin.
OK, first of all, I'm a rookie with Caché, so the code will probably be poor, but...
I need to be able to query the Caché database in Java in order to rebuild source files out of the Studio.
I can dump methods etc without trouble, however there is one thing which escapes me... For some reason, I cannot dump the properties of parameter EXTENTQUERYSPEC from class Samples.Person (namespace: SAMPLES).
The class reads like this in Studio:
Class Sample.Person Extends (%Persistent, %Populate, %XML.Adaptor)
{
Parameter EXTENTQUERYSPEC = "Name,SSN,Home.City,Home.State";
// etc etc
}
Here is the code of the procedure:
CREATE PROCEDURE CacheQc.getParamDesc(
IN className VARCHAR(50),
IN methodName VARCHAR(50),
OUT description VARCHAR(8192),
OUT type VARCHAR(50),
OUT defaultValue VARCHAR(1024)
) RETURNS NUMBER LANGUAGE COS {
set ref = className _ "||" _ methodName
set row = ##class(%Dictionary.ParameterDefinition).%OpenId(ref)
if (row = "") {
quit 1
}
set description = row.Description
set type = row.Type
set defaultValue = row.Default
quit 0
}
And the Java code:
private void getParamDetail(final String className, final String paramName)
throws SQLException
{
final String call
= "{ ? = call CacheQc.getParamDesc(?, ?, ?, ?, ?) }";
try (
final CallableStatement statement = connection.prepareCall(call);
) {
statement.registerOutParameter(1, Types.INTEGER);
statement.setString(2, className);
statement.setString(3, paramName);
statement.registerOutParameter(4, Types.VARCHAR);
statement.registerOutParameter(5, Types.VARCHAR);
statement.registerOutParameter(6, Types.VARCHAR);
statement.executeUpdate();
final int ret = statement.getInt(1);
// HERE
if (ret != 0)
throw new SQLException("failed to read parameter");
System.out.println(" description: " + statement.getString(4));
System.out.println(" type : " + statement.getString(5));
System.out.println(" default : " + statement.getString(6));
}
}
Now, for the aforementioned class/parameter pair the condition marked // HERE is always triggered and therefore the exception thrown... If I comment the whole line then I see that all three of OUT parameters are null, even defaultValue!
I'd have expected the latter to have the value mentioned in Studio...
So, why does this happen? Is my procedure broken somewhat?
In first you should check that you send right value for className and paramName, full name and in right case and. Why you choose storage procedures, when you can use select? And you can call your procedure in System Management Portal to see about probable errors.
select description, type,_Default "Default" from %Dictionary.ParameterDefinition where id='Sample.Person||EXTENTQUERYSPEC'
Your example, works well for me.
package javaapplication3;
import com.intersys.jdbc.CacheDataSource;
import java.sql.CallableStatement;
import java.sql.Connection;
import java.sql.SQLException;
import java.sql.Types;
public class JavaApplication3 {
/**
* #param args the command line arguments
*/
public static void main(String[] args) throws SQLException {
CacheDataSource ds = new CacheDataSource();
ds.setURL("jdbc:Cache://127.0.0.1:56775/Samples");
ds.setUser("_system");
ds.setPassword("SYS");
Connection dbconnection = ds.getConnection();
String call = "{ ? = call CacheQc.getParamDesc(?, ?, ?, ?, ?)}";
CallableStatement statement = dbconnection.prepareCall(call);
statement.registerOutParameter(1, Types.INTEGER);
statement.setString(2, "Sample.Person");
statement.setString(3, "EXTENTQUERYSPEC");
statement.registerOutParameter(4, Types.VARCHAR);
statement.registerOutParameter(5, Types.VARCHAR);
statement.registerOutParameter(6, Types.VARCHAR);
statement.executeUpdate();
int ret = statement.getInt(1);
System.out.println("ret = " + ret);
System.out.println(" description: " + statement.getString(4));
System.out.println(" type : " + statement.getString(5));
System.out.println(" default : " + statement.getString(6));
}
}
end result
ret = 0
description: null
type : null
default : Name,SSN,Home.City,Home.State
UPD:
try to change code of your procedure and add some debug like here
Class CacheQc.procgetParamDesc Extends %Library.RegisteredObject [ ClassType = "", DdlAllowed, Owner = {UnknownUser}, Not ProcedureBlock ]
{
ClassMethod getParamDesc(className As %Library.String(MAXLEN=50), methodName As %Library.String(MAXLEN=50), Output description As %Library.String(MAXLEN=8192), Output type As %Library.String(MAXLEN=50), Output defaultValue As %Library.String(MAXLEN=1024)) As %Library.Numeric(SCALE=0) [ SqlName = getParamDesc, SqlProc ]
{
set ref = className _ "||" _ methodName
set row = ##class(%Dictionary.ParameterDefinition).%OpenId(ref)
set ^debug($i(^debug))=$lb(ref,row,$system.Status.GetErrorText($g(%objlasterror)))
if (row = "") {
quit 1
}
set description = row.Description
set type = row.Type
set defaultValue = row.Default
quit 0
}
}
and after some test from java, check zw ^debug
SAMPLES>zw ^debug
^debug=4
^debug(3)=$lb("Sample.Person||EXTENTQUERYSPEC","31#%Dictionary.ParameterDefinition","ERROR #00: (no error description)")
Well, uh, I found the problem... Talk about stupid.
It happens that I had the Samples.Person class open in Studio and had made a "modification" to it; and deleted it just afterwards. Therefore the file was "as new"...
But the procedure doesn't seem to agree with this statement.
I closed the Studio where that file was, selected not to modify the "changes", reran the procedure again, and it worked...
Strangely enough, the SQL query worked even with my "fake modification". I guess it's a matter of some cache problem...
I'm using entity framework 4.
I have a stored procedure that just updates one value in my table, namely the application state ID. So I created a stored procedure that looks like this:
ALTER PROCEDURE [dbo].[UpdateApplicationState]
(
#ApplicationID INT,
#ApplicationStateID INT
)
AS
BEGIN
UPDATE
[Application]
SET
ApplicationStateID = #ApplicationStateID
WHERE
ApplicationID = #ApplicationID;
END
I created a function import called UpdateApplicationState. I had initially set its return type to null, but then it wasn't created in the context. So I changed its return type to int. Now it was created in the context. Is it wise to return something from my stored procedure?
Here is my method in my ApplicationRepository class:
public void UpdateApplicationState(int applicationID, int applicationStateID)
{
var result = context.UpdateApplicationState(applicationID, applicationStateID);
}
Here is my calling code to this method in my view:
applicationRepository.UpdateApplicationState(id, newApplicationStateID);
When I run it then I get the following error:
The data reader returned by the store
data provider does not have enough
columns for the query requested.
Any idea/advise on what I can do to get this to work?
Thanks
To get POCO to work with function imports that return null, you can customize the .Context.tt file like this.
Find the "Function Imports" named region (the section that starts with region.Begin("Function Imports"); and ends with region.End();) in the .Context.tt file and replace that whole section with the following:
region.Begin("Function Imports");
foreach (EdmFunction edmFunction in container.FunctionImports)
{
var parameters = FunctionImportParameter.Create(edmFunction.Parameters, code, ef);
string paramList = String.Join(", ", parameters.Select(p => p.FunctionParameterType + " " + p.FunctionParameterName).ToArray());
var isReturnTypeVoid = edmFunction.ReturnParameter == null;
string returnTypeElement = String.Empty;
if (!isReturnTypeVoid)
returnTypeElement = code.Escape(ef.GetElementType(edmFunction.ReturnParameter.TypeUsage));
#>
<# if (isReturnTypeVoid) { #>
<#=Accessibility.ForMethod(edmFunction)#> void <#=code.Escape(edmFunction)#>(<#=paramList#>)
<# } else { #>
<#=Accessibility.ForMethod(edmFunction)#> ObjectResult<<#=returnTypeElement#>> <#=code.Escape(edmFunction)#>(<#=paramList#>)
<# } #>
{
<#
foreach (var parameter in parameters)
{
if (!parameter.NeedsLocalVariable)
{
continue;
}
#>
ObjectParameter <#=parameter.LocalVariableName#>;
if (<#=parameter.IsNullableOfT ? parameter.FunctionParameterName + ".HasValue" : parameter.FunctionParameterName + " != null"#>)
{
<#=parameter.LocalVariableName#> = new ObjectParameter("<#=parameter.EsqlParameterName#>", <#=parameter.FunctionParameterName#>);
}
else
{
<#=parameter.LocalVariableName#> = new ObjectParameter("<#=parameter.EsqlParameterName#>", typeof(<#=parameter.RawClrTypeName#>));
}
<#
}
#>
<# if (isReturnTypeVoid) { #>
base.ExecuteFunction("<#=edmFunction.Name#>"<#=code.StringBefore(", ", String.Join(", ", parameters.Select(p => p.ExecuteParameterName).ToArray()))#>);
<# } else { #>
return base.ExecuteFunction<<#=returnTypeElement#>>("<#=edmFunction.Name#>"<#=code.StringBefore(", ", String.Join(", ", parameters.Select(p => p.ExecuteParameterName).ToArray()))#>);
<# } #>
}
<#
}
region.End();
What I'm doing here is instead of ignoring all function imports that return null, I'm creating a method that returns null. I hope this is helpful.
It is because you do not actually returning anything from your stored procedure. Add a line like below to your SP (SELECT ##ROWCOUNT), and it will be executing properly.
BEGIN
...
SELECT ##ROWCOUNT
END
While this solution will address your issue and actually returns the number of effected rows by your SP, I am not clear on why this is an issue for you:
I had initially set its return type to null, but then it wasn't created in the context.
When doing a Function Import, you can select "None" as return type and it will generate a new method on your ObjectContext with a return type of int. This method basically executes a stored procedure that is defined in the data source; discards any results returned from the function; and returns the number of rows affected by the execution.
EDIT: Why a Function without return value is ignored in a POCO Scenario:
Drilling into ObjectContext T4 template file coming with ADO.NET C# POCO Entity Generator reveals why you cannot see your Function in your ObjectContext class: Simply it's ignored! They escape to the next iteration in the foreach loop that generates the functions.
The workaround for this is to change the T4 template to actually generate a method for Functions without return type or just returning something based on the first solution.
region.Begin("Function Imports");
foreach (EdmFunction edmFunction in container.FunctionImports)
{
var parameters = FunctionImportParameter.Create(edmFunction.Parameters, code, ef);
string paramList = String.Join(", ", parameters.Select(p => p.FunctionParameterType + " " + p.FunctionParameterName).ToArray());
// Here is why a Function without return value is ignored:
if (edmFunction.ReturnParameter == null)
{
continue;
}
string returnTypeElement = code.Escape(ef.GetElementType(edmFunction.ReturnParameter.TypeUsage));
...
I'm attempting to parse SQL using the TSql100Parser provided by microsoft. Right now I'm having a little trouble using it the way it seems to be intended to be used. Also, the lack of documentation doesn't help. (example: http://msdn.microsoft.com/en-us/library/microsoft.data.schema.scriptdom.sql.tsql100parser.aspx )
When I run a simple SELECT statement through the parser it returns a collection of TSqlStatements which contains a SELECT statement.
Trouble is, the TSqlSelect statement doesn't contain attributes such as a WHERE clause, even though the clause is implemented as a class. http://msdn.microsoft.com/en-us/library/microsoft.data.schema.scriptdom.sql.whereclause.aspx
The parser does recognise the WHERE clause as such, looking at the token stream.
So, my question is, am I using the parser correctly? Right now the token stream seems to be the most useful feature of the parser...
My Test project:
public static void Main(string[] args)
{
var parser = new TSql100Parser(false);
IList<ParseError> Errors;
IScriptFragment result = parser.Parse(
new StringReader("Select col from T1 where 1 = 1 group by 1;" +
"select col2 from T2;" +
"select col1 from tbl1 where id in (select id from tbl);"),
out Errors);
var Script = result as TSqlScript;
foreach (var ts in Script.Batches)
{
Console.WriteLine("new batch");
foreach (var st in ts.Statements)
{
IterateStatement(st);
}
}
}
static void IterateStatement(TSqlStatement statement)
{
Console.WriteLine("New Statement");
if (statement is SelectStatement)
{
PrintStatement(sstmnt);
}
}
Yes, you are using the parser correctly.
As Damien_The_Unbeliever points out, within the SelectStatement there is a QueryExpression property which will be a QuerySpecification object for your third select statement (with the WHERE clause).
This represents the 'real' SELECT bit of the query (whereas the outer SelectStatement object you are looking at has just got the 'WITH' clause (for CTEs), 'FOR' clause (for XML), 'ORDER BY' and other bits)
The QuerySpecification object is the object with the FromClauses, WhereClause, GroupByClause etc.
So you can get to your WHERE Clause by using:
((QuerySpecification)((SelectStatement)statement).QueryExpression).WhereClause
which has a SearchCondition property etc. etc.
Quick glance around would indicate that it contains a QueryExpression, which could be a QuerySpecification, which does have the Where clause attached to it.
if someone lands here and wants to know how to get the whole elements of a select statement the following code explain that:
QuerySpecification spec = (QuerySpecification)(((SelectStatement)st).QueryExpression);
StringBuilder sb = new StringBuilder();
sb.AppendLine("Select Elements");
foreach (var elm in spec.SelectElements)
sb.Append(((Identifier)((Column)((SelectColumn)elm).Expression).Identifiers[0]).Value);
sb.AppendLine();
sb.AppendLine("From Elements");
foreach (var elm in spec.FromClauses)
sb.Append(((SchemaObjectTableSource)elm).SchemaObject.BaseIdentifier.Value);
sb.AppendLine();
sb.AppendLine("Where Elements");
BinaryExpression binaryexp = (BinaryExpression)spec.WhereClause.SearchCondition;
sb.Append("operator is " + binaryexp.BinaryExpressionType);
if (binaryexp.FirstExpression is Column)
sb.Append(" First exp is " + ((Identifier)((Column)binaryexp.FirstExpression).Identifiers[0]).Value);
if (binaryexp.SecondExpression is Literal)
sb.Append(" Second exp is " + ((Literal)binaryexp.SecondExpression).Value);
I had to split a SELECT statement into pieces. My goal was to COUNT how many record a query will return. My first solution was to build a sub query such as
SELECT COUNT(*) FROM (select id, name from T where cat='A' order by id) as QUERY
The problem was that in this case the order clause raises the error "The ORDER BY clause is not valid in views, inline functions, derived tables, sub-queries, and common table expressions, unless TOP or FOR XML is also specified"
So I built a parser that split a SELECT statment into fragments using the TSql100Parser class.
using Microsoft.Data.Schema.ScriptDom.Sql;
using Microsoft.Data.Schema.ScriptDom;
using System.IO;
...
public class SelectParser
{
public string Parse(string sqlSelect, out string fields, out string from, out string groupby, out string where, out string having, out string orderby)
{
TSql100Parser parser = new TSql100Parser(false);
TextReader rd = new StringReader(sqlSelect);
IList<ParseError> errors;
var fragments = parser.Parse(rd, out errors);
fields = string.Empty;
from = string.Empty;
groupby = string.Empty;
where = string.Empty;
orderby = string.Empty;
having = string.Empty;
if (errors.Count > 0)
{
var retMessage = string.Empty;
foreach (var error in errors)
{
retMessage += error.Identifier + " - " + error.Message + " - position: " + error.Offset + "; ";
}
return retMessage;
}
try
{
// Extract the query assuming it is a SelectStatement
var query = ((fragments as TSqlScript).Batches[0].Statements[0] as SelectStatement).QueryExpression;
// Constructs the From clause with the optional joins
from = (query as QuerySpecification).FromClauses[0].GetString();
// Extract the where clause
where = (query as QuerySpecification).WhereClause.GetString();
// Get the field list
var fieldList = new List<string>();
foreach (var f in (query as QuerySpecification).SelectElements)
fieldList.Add((f as SelectColumn).GetString());
fields = string.Join(", ", fieldList.ToArray());
// Get The group by clause
groupby = (query as QuerySpecification).GroupByClause.GetString();
// Get the having clause of the query
having = (query as QuerySpecification).HavingClause.GetString();
// Get the order by clause
orderby = ((fragments as TSqlScript).Batches[0].Statements[0] as SelectStatement).OrderByClause.GetString();
}
catch (Exception ex)
{
return ex.ToString();
}
return string.Empty;
}
}
public static class Extension
{
/// <summary>
/// Get a string representing the SQL source fragment
/// </summary>
/// <param name="statement">The SQL Statement to get the string from, can be any derived class</param>
/// <returns>The SQL that represents the object</returns>
public static string GetString(this TSqlFragment statement)
{
string s = string.Empty;
if (statement == null) return string.Empty;
for (int i = statement.FirstTokenIndex; i <= statement.LastTokenIndex; i++)
{
s += statement.ScriptTokenStream[i].Text;
}
return s;
}
}
And to use this class simply:
string fields, from, groupby, where, having, orderby;
SelectParser selectParser = new SelectParser();
var retMessage = selectParser.Parse("SELECT * FROM T where cat='A' Order by Id desc",
out fields, out from, out groupby, out where, out having, out orderby);