lundi 12 mars 2012

Select Statement Syntax [AX 2012]


SelectStatement
=
select Parameters
Parameters
[ [  FindOptions  ] [  FieldList  from ] ] TableBufferVariable [ IndexClause ] [ Options  ] [  WhereClause  ] [  JoinClause  ]
FindOptions
=
crossCompany | reverse | firstFast | [ firstOnly | firstOnly10 | firstOnly100 |firstOnly1000 ] | forUpdate | noFetch | [forcePlaceholders | forceLiterals] |forceselectorder | forceNestedLoop | repeatableRead | validTimeState
FieldList
=
Field  { ,  Field  } | *
Field
=
Aggregate  (  FieldIdentifier  ) |  FieldIdentifier
Aggregate
=
sum | avg | minof | maxof | count
Options
=
[ order by , group by ,  FieldIdentifier  [ asc | desc ] { ,  FieldIdentifier  [ asc |desc ] }] | [  IndexClause  ]
IndexClause
=
index  IndexName | index hint  IndexName
WhereClause
=
where  Expression
JoinClause
=
[exists | notexists | outer ] join  Parameters
KeywordDescriptionExample
asc
An option on the order by orgroup by clause. The sorting is ascending. (Sort is ascending by default.)
select * from custTable
    order by Name asc;
avg
Returns the average of the fields.
CustTable custTable;
;
select avg(value) from custTable;
print custTable.value;
count
Returns the number of records.
CustTable xCT;
int64 iCountRows; ;
Select COUNT(RecID) from xCT;
iCountRows = xCT.RecID;
crossCompany
Returns data for all companies that the user is authorized to read from. (A container can be added to reduce the number of companies involved.)
CustTable custTable;
container conCompanies = ['dat','dmo'];
;
select crossCompany :conCompanies
    * from custTable;
desc
An option on the order by orgroup by clause. The sorting is descending.
select * from custTable
    order by Name desc;
exists
A method that returns a Boolean value and a join clause.
while select AccountNum, Name from custTable
    order by AccountNum
    exists join * from ctr
    where (ctr.AccountNum ==
      custTable.AccountNum)
firstFast
A priority hint. The first row appears more quickly but the total return time for this option might be slower. The firstFast hint is automatically issued from all forms, but is rarely used directly from X++.
select firstFast custTable
    order by AccountNum;
firstOnly
Speeds up the fetch. Instructs MorphX to fetch only the first record.
static InventTable find(
    ItemId   itemId,
    boolean  update = false)
{
    InventTable inventTable;
    ;
    inventTable.selectForUpdate
        (update);
    if (itemId)
    {
         select firstonly inventTable
            index hint ItemIdx
            where inventTable.itemId
                == itemId;
    }
    return inventTable;
}
firstOnly10
Same as firstOnly, except returns 10 rows instead of one.
firstOnly100
Same as firstOnly, except returns 100 rows instead of one.
firstOnly1000
Same as firstOnly, except returns 1000 rows instead of one.
forceLiterals
NoteNote
You are advised not to use theforceLiterals keyword in X++select statements, because it could expose code to an SQL injection security threat.
forceLiterals instructs the kernel to reveal the actual values that are used in where clauses to the Microsoft SQL Server database at the time of optimization.
forceLiterals andforcePlaceholders are mutually exclusive.
forceNestedLoop
Forces the Microsoft SQL Server database to use a nested-loop algorithm to process a particular SQL statement containing a join algorithm. This means that a record from the first table is fetched before any records from the second table are fetched. Typically, other join algorithms, such as hash-joins and merge-joins, would be considered. This keyword is often combined with the forceSelectOrder keyword.
while select forceSelectOrder
    forceNestedLoop inventTransThis
    index hint TransIdIdx
    where inventTransThis.InventTransId
        == inventTrans.InventTransId
        && inventTransThis.StatusIssue
        <= StatusIssue::ReservOrdered
forcePlaceholders
Instructs the kernel not to reveal the actual values used in whereclauses to the SQL Server database at the time of optimization. This is the default in all statements that are not join statements.
The advantage of using this keyword is that the kernel can reuse the access plan for other similar statements with other search values. The disadvantage is that the access plan is computed without taking into consideration that data distribution might not be even. The access plan is an on-average access plan.
forcePlaceholders andforceLiterals are mutually exclusive.
static void forcePlaceHoldersExample(Args _args)
{
    SalesTable salesTable;
    SalesLine salesLine;
    ;
    while select forcePlaceholders salesLine
        join salesTable
           where salesTable.SalesId ==
            salesLine.SalesId
               && salesTable.SalesId == '10'
    {
        //more code
    }
}
forceSelectOrder
Forces the SQL Server database to access the tables in a join in the specified order. If two tables are joined, the first table in the statement is always accessed first. This keyword is often combined with the forceNestedLoopkeyword.
display ForecastHasPurch hasForecastPurch()
{
    ForecastPurch   forecastPurch;
    InventDim       inventDim;
    ;
    select firstOnly forcePlaceholders
        forceSelectOrder recId
        from forecastPurch
        index hint ItemIdx
        where forecastPurch.itemId == this.itemId
    exists join inventDim
        index hint DimIdIdx
        where inventDim.inventDimId ==
            forecastPurch.inventDimId
        && inventDim.configId == this.configId;
    return forecastPurch.recId;
}
forUpdate
Selects records exclusively for update. Depending on the underlying database, the records may be locked for other users.
ttsBegin;
while select forUpdate ledgerJournalTrans
    index hint NumVoucherIdx
    where ledgerJournalTrans.journalNum ==
    _journalNum &&
    ledgerJournalTrans.voucher == _voucher
{
    ledgerJournalTrans.doDelete();
    counter++;
}
if (counter
    && ledgerJournalTable.journalType
    != LedgerJournalType::Periodic)
{
    NumberSeq::release(
      ledgerJournalTable.voucherSeries,
      _voucher);
}
ttsCommit;
group by
Instructs the database to group selected records by fields.
CustTable custTable;
;
while select sum(CreditMax) from custTable
    group by CustGroup
{
    print custTable.CustGroup, " ",custTable.CreditMax;
}
index
Instructs the database to sort the selected records as defined by the index.
CustTable custTable;
;
while select AccountNum, Name from custTable
    index AccountIdx
{
    print custTable.AccountNum, " ", custTable.Name;
}
index hint
Gives the database a hint to use this index to sort the selected records as defined by the index. The database can ignore the hint.
NoteNote
A wrong index hint can have a big performance impact. Index hints should only be applied to SQL statements that do not have dynamic where clauses ororder by clauses, and where the effect of the hint can be verified.
while select forUpdate ledgerJournalTrans
    index hint NumVoucherIdx
    where ledgerJournalTrans.journalNum
        == _journalNum
join
Used to join tables on a column that is common to both tables. The join criteria are specified in thewhere clause because there is noon keyword in X++ SQL.
Reduces the number of SQL statements that are needed if you want to loop through a table and update transactions in a related table.
For example, if you process 500 records in a table, and want to update related records in another table, and use a nested while select to do this, there will be 501 trips to the database. If you use a join, there will be a single trip to the database.
while select ledgerTable
    join ledgerTrans
        where ledgerTrans.accountNum ==
            ledgerTable.accountNum
    {
        amountMST += ledgerTrans.amountMST;
    }
maxof
Returns the maximum of the fields.
CustTable custTable;
;
select maxof(CreditMax) from custTable;
minof
Returns the minimum of the fields.
CustTable custTable;
;
select minof(CreditMax) from custTable;
noFetch
Indicates that no records are to be fetched at present. This is typically used when the result of the select is passed on to another application object, for example, a query that performs the actual fetch.
select noFetch custTable
    order by AccountNum
notExists
Chosen only if there are no posts.
while select AccountNum, Name from custTable
    order by AccountNum
    notExists join * from ctr
    where (ctr.AccountNum ==
        custTable.AccountNum)
optimisticLock
Forces a statement to run with Optimistic Concurrency Control even if a different value is set on the table.
For more information, seeOptimistic Concurrency Control.
select optimisticLock custTable
    where custTable.AccountNum > '1000'
order by
Instructs the database to sort the selected records by fields in theorder by list.
select * from custTable
    order by accountNum desc
    where custTable.AccountNum > "100";
outer
Returns all rows from the first-named table, including rows that have no match in the second-named table. This is a left outer join, although there is no leftkeyword. There is no right outer join in X++ SQL.
X++
while select AccountNum
 from custTable
 order by AccountNum
 outer join * from custBankAccount
 where custBankAccount.AccountNum ==
    custTable.AccountNum
{
 print custTable.AccountNum,
    " , ", custBankAccount.DlvMode;
}
pause;
pessimisticLock
Forces a statement to run with Pessimistic Concurrency Control even if a different value is set on the table.
For more information, seeOptimistic Concurrency Control.
select pessimisticLock custTable
    where custTable.AccountNum > '1000';
repeatableRead
Specifies that no other transactions can modify data that has been read by logic inside the current transaction, until after the current transaction completes.
An explicit transaction completes at either ttsAbort or at the outermostttsCommit.
For a stand-alone selectstatement, the transaction duration is the duration of the selectcommand. However, the database sometimes enforces the equivalent of repeatableRead in individualselect statements even without this keyword appearing in your X++ code (depending on how the database decides to scan the tables).
For more information, see the documentation for the underlying relational database product.
reverse
Records are returned in reverse order.
select reverse custTable
    order by AccountNum;
sum
Returns the sum of the fields. Can be used to sum all accounts, order lines, and so on.
CustTable custTable;
;
select sum(CreditMax) from custTable;
validTimeState
Filters rows from a table that has its ValidTimeStateFieldTypeproperty set to a value other thanNone. For more information, seeValid Time State Tables and Date Effective Data.
X++
static void VtsJob1(Args _args)
{
    // A VTS table in AX 2012.
    CustPackingSlipTransHistory xrec1;
    utcDateTime myDateFrom , myDateTo;
    anytype myAnytype = -1;

    myDateFrom = DateTimeUtil::utcNow();
    myDateTo = myDateFrom;

    SELECT 
        validTimeState(myDateFrom, myDateTo)
            *
        FROM xrec1;

    myAnytype = xrec1.getFieldValue("RecId");
    info(myAnytype);
}
à

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