Search Results

Search found 27691 results on 1108 pages for 'multi select'.

Page 217/1108 | < Previous Page | 213 214 215 216 217 218 219 220 221 222 223 224  | Next Page >

  • Using 'in' in Join

    - by Ruslan
    i have two selects a & b and i join them like: select * from ( select n.id_b || ',' || s.id_b ids, n.name, s.surname from names n, surnames s where n.id_a = s.id_a ) a left join ( select sn.id, sn.second_name ) b on b.id in (a.ids) in this case join doesn't work :( The problem is in b.id in (a.ids). But why if it looks like 12 in (12,24) and no result :(

    Read the article

  • How do I accurately handle a batch seperator for SQL from C#

    - by Sam Saffron
    For Data Explorer I would like to add support for a Batch separator. So for example if users type in: select 'GO' go select 1 as go Go select 100 I would like to return the three result sets. Its clear that I need some sort of parser here, my hope is that this is a solved problem and I can just plug it in. (writing a full T-SQL parser is not something I would like to do) What component / demo code could achieve splitting this batch into its 3 parts?

    Read the article

  • Calculating a date when a date has been chosen by the number of days

    - by Andy
    I have three selection drop downs in a form comprising of day, month, year. Pretty standard. Ive omitted all the individual select options for the purposes of this question. <label for="start_date">Start Date<font class="required">*</font>:</label> <select name="place_booking[day_val]"> <select name="place_booking[month_val]"> <select name="place_booking[year_val]"> Underneath this i have a selection for the number of days the client wishes to stay at the letting. <label for="number_of_days">Number of Days<font class="required">*</font>:</label> <select name="place_booking[number_of_days]"> Underneath there is a space to display the departure date based on there two selections above. <label for="departure_date">Departure Date<font class="required">*</font>:</label> ? - this bit i would like to display the calculated date after the above is selected Any help would be grealty appreciated.

    Read the article

  • What can be used instead of Datatable in LINQ

    - by Kabi
    I have a SQL query that returns a Datatable: var routesTable = _dbhelper.Select("SELECT [RouteId],[UserId],[SourceName],[CreationTime] FROM [Routes] WHERE UserId=@UserId AND RouteId=@RouteId", inputParams); and then we can work with Datatable object of routesTable if (routesTable.Rows.Count == 1) { result = new Route(routeId) { Name = (string)routesTable.Rows[0]["SourceName"], Time = routesTable.Rows[0]["CreationTime"] is DBNull ? new DateTime() : Convert.ToDateTime(routesTable.Rows[0]["CreationTime"]) }; result.TrackPoints = GetTrackPointsForRoute(routeId); } I want to change this code to linq but I don't know how can I simulate Datatable in LINQ ,I wrote this part: Route result = null; aspnetdbDataContext aspdb = new aspnetdbDataContext(); var Result = from r in aspdb.RouteLinqs where r.UserId == userId && r.RouteId==routeId select r; .... but I don't know how can I change this part: if (routesTable.Rows.Count == 1) { result = new Route(routeId) { Name = (string)routesTable.Rows[0]["SourceName"], Time = routesTable.Rows[0]["CreationTime"] is DBNull ? new DateTime() : Convert.ToDateTime(routesTable.Rows[0]["CreationTime"]) }; would you please tell me how can I do this? EDIT here you can see the whole block of code in original public Route GetById(int routeId, Guid userId) { Route result = null; var inputParams = new Dictionary<string, object> { {"UserId", userId}, {"RouteId", routeId} }; var routesTable = _dbhelper.Select("SELECT [RouteId],[UserId],[SourceName],[CreationTime] FROM [Routes] WHERE UserId=@UserId AND RouteId=@RouteId", inputParams); if (routesTable.Rows.Count == 1) { result = new Route(routeId) { Name = (string)routesTable.Rows[0]["SourceName"], Time = routesTable.Rows[0]["CreationTime"] is DBNull ? new DateTime() : Convert.ToDateTime(routesTable.Rows[0]["CreationTime"]) }; result.TrackPoints = GetTrackPointsForRoute(routeId); } return result; }

    Read the article

  • One-way platforms in UDK

    - by Jordaan Mylonas
    I'm looking to make a multi-player platforming game using UDK. I'm currently doing feasibility research, to make sure I will reasonably be able to do all of the technical things I want to do. The first major hurdle I've come across without being able to find as answer, are one-way platforms. That is to say, platforms through which a player can jump up, but not fall through (unless they choose to). These are commonly seen in games like Mario, Kirby and Smash Bros. Does anyone know how such a system would work within UDK? I can think of solutions that might work for single-player, but not multi.

    Read the article

  • How to turn this linq query to lazy loading

    - by Luke101
    I would like to make a certain select item to lazy load latter in my linq query. Here is my query var posts = from p in context.post where p.post_isdeleted == false && p.post_parentid == null select new { p.post_date, p.post_id, p.post_titleslug, p.post_votecount, FavoriteCount = context.PostVotes.Where(x => x.PostVote_postid == p.post_id).Count() //this should load latter }; I have deleted the FavoriteCount item in the select query and would like it to ba added later based on certain conditions. Here is the way I have it lazy loaded if (GetFavoriteInfo) { posts = posts.Select(x => new { FavoriteCount = context.PostVotes.Where(y => y.PostVote_postid == x.post_id).Count() }); } I am getting a syntax error with this the above query. How do I fix this

    Read the article

  • Creating a function in Postgresql that does not return composite values

    - by celenius
    I'm learning how to write functions in Postgresql. I've defined a function called _tmp_myfunction() which takes in an id and returns a table (I also define a table object type called _tmp_mytable) -- create object type to be returned CREATE TYPE _tmp_mytable AS ( id integer, cost double precision ); -- create function which returns query CREATE OR REPLACE FUNCTION _tmp_myfunction( id integer ) RETURNS SETOF _tmp_mytable AS $$ BEGIN RETURN QUERY SELECT id, cost FROM sales WHERE id = sales.id; END; $$ LANGUAGE plpgsql; This works fine when I use one id and call it using the following approach: SELECT * FROM _tmp_myfunction(402); What I would like to be able to do is to call it, but to use a column of values instead of just one value. However, if I use the following approach I end up with all values of the table in one column, separated by commas: -- call function using all values in a column SELECT _tmp_myfunction(t.id) FROM transactions as t; I understand that I can get the same result if I use SELECT _tmp_myfunction(402); instead of SELECT * FROM _tmp_myfunction(402); but I don't know how to construct my query in such a way that I can separate out the results.

    Read the article

  • jquery selecting element by data attribute

    - by zizo
    Is there an easy and straight-forward method to select elements based on their data attribute? For example, select all anchors that has data attribute named customerID which has value of 22. I am kind of hesitant to use rel or other attributes to store such information, but I find it much harder to select an element based on what data is stored in it. Thanks!

    Read the article

  • Need an alternative to two left joins.

    - by Scarface
    Hey guys quick question, I always use left join, but when I left join twice I always get funny results, usually duplicates. I am currently working on a query that Left Joins twice to retrieve the necessary information needed but I was wondering if it were possible to build another select statement in so then I do not need two left joins or two queries or if there were a better way. For example, if I could select the topic.creator in table.topic first AS something, then I could select that variable in users and left join table.scrusersonline. Thanks in advance for any advice. SELECT * FROM scrusersonline LEFT JOIN users ON users.id = scrusersonline.id LEFT JOIN topic ON users.username = topic.creator WHERE scrusersonline.topic_id = '$topic_id' The whole point of this query is to check if the topic.creator is online by retrieving his name from table.topic and matching his id in table.users, then checking if he is in table.scrusersonline. It produces duplicate entries unfortunately and is thus inaccurate in my mind.

    Read the article

  • Problem with Postgres FOR LOOP

    - by user341831
    Hi all, Ich have a problem in postgres function: CREATE OR REPLACE FUNCTION linkedRepoObjects(id bigint) RETURNS int AS $$ DECLARE catNumber int DEFAULT 0; DECLARE cat RECORD; BEGIN WITH RECURSIVE children(categoryid,category_fk) AS ( SELECT categoryid, category_fk FROM b2m.category_tab WHERE categoryid = 1 UNION ALL SELECT c1.categoryid,c1.category_fk FROM b2m.category_tab c1, children WHERE children.categoryid = c1.category_fk ) FOR cat IN SELECT * FROM children LOOP IF EXISTS (SELECT 1 FROM b2m.repoobject_tab WHERE category_fk = cat.categoryid) THEN catNumber = catNumber +1 END IF; END LOOP; RETURN catNumber; END; $$ LANGUAGE 'plpgsql'; I've got error: FEHLER: Syntaxfehler bei »FOR« LINE 1: ...dren WHERE children.categoryid = c1.category_fk ) FOR $2 I... I'm a newbee in Postgres. Please help. Thanx in advance

    Read the article

  • How to use group by and having count in Linq

    - by Luke
    I am having trouble trying to convert the following query from SQL to Linq, in particular with the having count and group by parts of the query: select ProjectID from ProjectAssociation where TeamID in ( select TeamID from [User] where UserID in (4)) group by ProjectID having COUNT(TeamID) = (select distinct COUNT(TeamID) from [User] where UserID in (4)) Any advice on how to do so would be much appreciated.

    Read the article

  • Watchpoints w/xDebug in Eclipse PDT?

    - by continuum
    Has anyone gotten watchpoints to work when debugging PHP with xDebug and Eclipse? The way I understand it, I'm supposed to be able to select a watched variable in the expressions view or select a variable in the Variables view during debugging, and then select Run-Toggle Watchpoint. But Toggle Watchpoint is constantly greyed out. All my other debugging functions work fine: breakpoints, step in, out, over, etc. Just can't get a watchpoint working.

    Read the article

  • How best to associate code with events in jQuery?

    - by Ned Batchelder
    Suppose I have a <select> element on my HTML page, and I want to run some Javascript when the selection is changed. I'm using jQuery. I have two ways to associate the code with the element. Method 1: jQuery .change() <select id='the_select'> <option value='opt1'>One</option> <option value='opt2'>Two</option> </select> <script> $('#the_select').change(function() { alert('Changed!'); }); </script> Method 2: onChange attribute <select id='the_select' onchange='selectChanged();'> <option value='opt1'>One</option> <option value='opt2'>Two</option> </select> <script> function selectChanged() { alert('Changed!'); } </script> I understand the different modularity here: for example, method 1 keeps code references out of the HTML, but method 2 doesn't need to mention HTML ids in the code. What I don't understand is: are there operational differences between these two that would make me prefer one over the other? For example, are there edge-case browsers where one of these works and the other doesn't? Is the integration with jQuery better for either? Does the late-binding of the code to the event make a difference in the behavior of the page? Which do you pick and why?

    Read the article

  • Linq to Entities custom ordering via position mapping table

    - by Bigfellahull
    Hi, I have a news table and I would like to implement custom ordering. I have done this before via a positional mapping table which has newsIds and a position. I then LEFT OUTER JOIN the position table ON news.newsId = position.itemId with a select case statement CASE WHEN [position] IS NULL THEN 9999 ELSE [position] END and order by position asc, articleDate desc. Now I am trying to do the same with Linq to Entities. I have set up my tables with a PK, FK relationship so that my News object has an Entity Collection of positions. Now comes the bit I can't work out. How to implement the LEFT OUTER JOIN. I have so far: var query = SelectMany (n => n.Positions, (n, s) => new { n, s }) .OrderBy(x => x.s.position) .ThenByDescending(x => x.n.articleDate) .Select(x => x.n); This kinda works. However this uses a INNER JOIN so not what I am after. I had another idea: ret = ret.OrderBy(n => n.ShufflePositions.Select(s => s.position)); However I get the error DbSortClause expressions must have a type that is order comparable. I also tried ret = ret.GroupJoin(tse.ShufflePositions, n => n.id, s => s.itemId, (n, s) => new { n, s }) .OrderBy(x => x.s.Select(z => z.position)) .ThenByDescending(x => x.n.articleDate) .Select(x => x.n); but I get the same error! If anyone can help me out, it would be much appreciated!

    Read the article

  • Date ranges intersections..

    - by Puzzled
    MS Sql 2008: I have 3 tables: meters, transformers (Ti) and voltage transformers (Tu) ParentId MeterId BegDate EndDate 10 100 '20050101' '20060101' ParentId TiId BegDate EndDate 10 210 '20050201' '20050501' 10 220 '20050801' '20051001' ParentId TuId BegDate EndDate 10 300 '20050801' '20050901' where date format is yyyyMMdd (year-month-day) Is there any way to get periods intersection and return the table like this? ParentId BegDate EndDate MeterId TiId TuId 10 '20050101' '20050201' 100 null null 10 '20050201' '20050501' 100 210 null 10 '20050501' '20050801' 100 null null 10 '20050801' '20050901' 100 220 300 10 '20050901' '20051001' 100 220 null 10 '20051001' '20060101' 100 null null Here is the table creation script: --meters declare @meters table (ParentId int, MeterId int, BegDate smalldatetime, EndDate smalldatetime ) insert @meters select 10, 100, '20050101', '20060101' --transformers declare @ti table (ParentId int, TiId int, BegDate smalldatetime, EndDate smalldatetime ) insert @ti select 10, 210, '20050201', '20050501' union all select 10, 220, '20050801', '20051001' --voltage transformers declare @tu table (ParentId int, TuId int, BegDate smalldatetime, EndDate smalldatetime ) insert @tu select 10, 300, '20050801', '20050901'

    Read the article

  • Xalan redirect:write , use either of two element values to create name of new .xml file depending on

    - by Bilzac
    So I have the following code: <redirect:write select="concat('..\\folder\\,string(filename),'.xml')"> Where "filename" is a tag in the xml source. My problem occurs when filename is null or blank. And this is the case for several of the xml filename tags. So what I am trying to implement is a checking method. This is what I have done: <xsl-if test = "filename != ''"> <xsl:variable name = "tempName" select = "filename" /> </xsl-if> <xsl-if test ="filename = ''"> <xsl:variable name = "tempName" select = "filenameB"/> </xsl-if> <redirect:write select="concat('..\\folder\\,string($tempName),'.xml')"> I seem to be getting NPEs when I compile my Java code, saying the Variable not resolvable: tempName

    Read the article

  • How do I accurately handle a batch separator for SQL from C#

    - by Sam Saffron
    For Data Explorer I would like to add support for a Batch separator. So for example if users type in: select 'GO' go select 1 as go Go select 100 I would like to return the three result sets. Its clear that I need some sort of parser here, my hope is that this is a solved problem and I can just plug it in. (writing a full T-SQL parser is not something I would like to do) What component / demo code could achieve splitting this batch into its 3 parts?

    Read the article

  • Extending Zend DB Table to include BETWEEN and LIMIT.

    - by davykiash
    Am looking for how I can extend the Zend_DB_Table below to accomodate a BETWEEN two dates syntax and LIMIT syntax My current construct is class Model_DbTable_Tablelist extends Zend_Db_Table_Abstract { protected $_name = 'mytable'; $select = $this->select() ->setIntegrityCheck(false) ->from('mytable', array('MyCol1', 'MyDate')); } I want it extended to be equivalent to the query below SELECT MyCol1,MyDate FROM mytable WHERE MyDate BETWEEN '2008-04-03' AND '2009-01-02' LIMIT 0,20 Any ideas?

    Read the article

  • SQL Group By equivalent

    - by MikeB
    Pretend I have a cupcake_rating table: id | cupcake | delicious_rating -------------------------------------------- 1 | Strawberry | Super Delicious 2 | Strawberry | Mouth Heaven 3 | Blueberry | Godly 4 | Blueberry | Super Delicious I want to find all the cupcakes that have a 'Super Delicious' AND 'Mouth Heaven' rating. I feel like this is easily achievable using a group by clause and maybe a having. I was thinking: select distinct(cupcake) from cupcake_rating group by cupcake having delicious_rating in ('Super Delicious', 'Mouth Heaven') I know I can't have two separate AND statements. I was able to achieve my goal using: select distinct(cupcake) from cupcake_rating where cupcake in ( select cupcake from cupcake_rating where delicious_rating = 'Super Delicious' ) and cupcake in ( select cupcake from cupcake_rating where delicious_rating = 'Mouth Heaven' ) This will not be satisfactory because once I add a third type of rating I am looking for, the query will take hours (there are a lot of cupcake ratings).

    Read the article

  • MySQL inconsistent table scan results

    - by user148207
    What's going on here? mysql> select count(*) from notes where date(updated_at) > date('2010-03-25'); +----------+ | count(*) | +----------+ | 0 | +----------+ 1 row in set (0.59 sec) mysql> select count(*) from notes where message like'%***%' and date(updated_at) > date('2010-03-25'); +----------+ | count(*) | +----------+ | 26 | +----------+ 1 row in set (1.30 sec) mysql> explain select count(*) from notes where date(updated_at) > date('2010-03-25'); +----+-------------+-------+------+---------------+------+---------+------+--------+-------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+-------+------+---------------+------+---------+------+--------+-------------+ | 1 | SIMPLE | notes | ALL | NULL | NULL | NULL | NULL | 588106 | Using where | +----+-------------+-------+------+---------------+------+---------+------+--------+-------------+ 1 row in set (0.07 sec) mysql> explain select updated_at from notes where message like'%***%' and date(updated_at) > date('2010-03-25'); +----+-------------+-------+------+---------------+------+---------+------+--------+-------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+-------+------+---------------+------+---------+------+--------+-------------+ | 1 | SIMPLE | notes | ALL | NULL | NULL | NULL | NULL | 588106 | Using where | +----+-------------+-------+------+---------------+------+---------+------+--------+-------------+ 1 row in set (0.09 sec) mysql>

    Read the article

  • Does clustered index on foreign key column increase join performance vs non-clustered ?

    - by alpav
    In many places it's recommended that clustered indexes are better utilized when used to select range of rows using BETWEEN statement. When I select joining by foreign key field in such a way that this clustered index is used, I guess, that clusterization should help too because range of rows is being selected even though they all have same clustered key value and BETWEEN is not used. Considering that I care only about that one select with join and nothing else, am I wrong with my guess ?

    Read the article

  • Looping through all attributes of a XML element in XSLT

    - by TheGNUGuy
    Hey everyone, I am trying to use <xsl:for-each select="@*"> to grab all the attributes of a given element but when i do that my <xsl:choose> statement doesn't execute. Here is the element that I'm working with: <textBox id="Airfare" value="" label="text 1"/> Here is the XSLT template I'm using: <xsl:template match="textBox"> <div> <xsl:choose> <xsl:when test="@label"> <xsl:value-of select="@label"/> </xsl:when> <xsl:otherwise> <xsl:text>No Label Defined</xsl:text> </xsl:otherwise> </xsl:choose> <xsl:element name="input"> <xsl:attribute name="type">text</xsl:attribute> <xsl:for-each select="@*"> <xsl:choose> <xsl:when test="@id"> <xsl:attribute name="name">form_<xsl:value-of select="@id"/></xsl:attribute> <xsl:attribute name="id">form_<xsl:value-of select="@id"/></xsl:attribute> </xsl:when> <xsl:when test="@label"> </xsl:when> <xsl:otherwise> <xsl:copy-of select="current()"/> </xsl:otherwise> </xsl:choose> </xsl:for-each> </xsl:element> </div> And when I generate the HTML using PHP I get this: <div>text 1<input type="text" id="Airfare" value="" label="text 1"></div> As you can see it didn't add form_ to the id attribute it didn't generate a name attribute and it didn't skip over the label attribute. Thanks for your help!

    Read the article

  • how to Invoke User-Defined Functions That Return a Table Data Type

    - by nectar
    here my code- create function dbo.emptable() returns Table as return (select id, name, salary from employee) go select dbo.emptable() error: Msg 4121, Level 16, State 1, Line 1 Cannot find either column "dbo" or the user-defined function or aggregate "dbo.emptable", or the name is ambiguous. while when I run sp_helptext emptable it shows- create function dbo.emptable() returns Table as return (select id, name, salary from employee) it means function exists in database then why it is giving such error?

    Read the article

  • Why won't C# accept a (seemingly) perfectly good Sql Server CE Query?

    - by VoidKing
    By perfectly good sql query, I mean to say that, inside WebMatrix, if I execute the following query, it works to perfection: SELECT page AS location, (len(page) - len(replace(UPPER(page), UPPER('o'), ''))) / len('o') AS occurences, 'pageSettings' AS tableName FROM PageSettings WHERE page LIKE '%o%' UNION SELECT pageTitle AS location, (len(pageTitle) - len(replace(UPPER(pageTitle), UPPER('o'), ''))) / len('o') AS occurences, 'ExternalSecondaryPages' AS tableName FROM ExternalSecondaryPages WHERE pageTitle LIKE '%o%' UNION SELECT eventTitle AS location, (len(eventTitle) - len(replace(UPPER(eventTitle), UPPER('o'), ''))) / len('o') AS occurences, 'MainStreetEvents' AS tableName FROM MainStreetEvents WHERE eventTitle LIKE '%o%' Here i am using 'o' as a static search string to search upon. No problem, but not exeactly very dynamic. Now, when I write this query as a string in C# and as I think it should be (and even as I have done before) I get a server-side error indicating that the string was not in the correct format. Here is a pic of that error: And (although I am only testing the output, should I get it to quit erring), here is the actual C# (i.e., the .cshtml) page that queries the database: @{ Layout = "~/Layouts/_secondaryMainLayout.cshtml"; var db = Database.Open("Content"); string searchText = Request.Unvalidated["searchText"]; string selectQueryString = "SELECT page AS location, (len(page) - len(replace(UPPER(page), UPPER(@0), ''))) / len(@0) AS occurences, 'pageSettings' AS tableName FROM PageSettings WHERE page LIKE '%' + @0 + '%' "; selectQueryString += "UNION "; selectQueryString += "SELECT pageTitle AS location, (len(pageTitle) - len(replace(UPPER(pageTitle), UPPER(@0), ''))) / len(@0) AS occurences, 'ExternalSecondaryPages' AS tableName FROM ExternalSecondaryPages WHERE pageTitle LIKE '%' + @0 + '%' "; selectQueryString += "UNION "; selectQueryString += "SELECT eventTitle AS location, (len(eventTitle) - len(replace(UPPER(eventTitle), UPPER(@0), ''))) / len(@0) AS occurences, 'MainStreetEvents' AS tableName FROM MainStreetEvents WHERE eventTitle LIKE '%' + @0 + '%'"; @:beginning <br/> foreach (var row in db.Query(selectQueryString, searchText)) { @:entry @:@row.location &nbsp; @:@row.occurences &nbsp; @:@row.tableName <br/> } } Since it is erring on the foreach (var row in db.Query(selectQueryString, searchText)) line, that heavily suggests that something is wrong with my query, however, everything seems right to me about the syntax here and it even executes to perfection if I query the database (mind you, un-parameterized) directly. Logically, I would assume that I have erred somewhere with the syntax involved in parameterizing this query, however, my double and triple checking (as well as, my past experience at doing this) insists that everything looks fine here. Have I messed up the syntax involved with parameterizing this query, or is something else at play here that I am overlooking? I know I can tell you, for sure, as it has been previously tested, that the value I am getting from the query string is, indeed, what I would expect it to be, but as there really isn't much else on the .cshtml page yet, that is about all I can tell you.

    Read the article

  • 12c - Invisible Columns...

    - by noreply(at)blogger.com (Thomas Kyte)
    Remember when 11g first came out and we had "invisible indexes"?  It seemed like a confusing feature - indexes that would be maintained by modifications (hence slowing them down), but would not be used by queries (hence never speeding them up).  But - after you looked at them a while, you could see how they can be useful.  For example - to add an index in a running production system, an index used by the next version of the code to be introduced later that week - but not tested against the queries in version one of the application in place now.  We all know that when you add an index - one of three things can happen - a given query will go much faster, it won't affect a given query at all, or... It will make some untested query go much much slower than it used to.  So - invisible indexes allowed us to modify the schema in a 'safe' manner - hiding the change until we were ready for it.Invisible columns accomplish the same thing - the ability to introduce a change while minimizing any negative side effects of that change.  Normally when you add a column to a table - any program with a SELECT * would start seeing that column, and programs with an INSERT INTO T VALUES (...) would pretty much immediately break (an INSERT without a list of columns in it).  Now we can add a column to a table in an invisible fashion, the column will not show up in a DESCRIBE command in SQL*Plus, it will not be returned with a SELECT *, it will not be considered in an INSERT INTO T VALUES statement.  It can be accessed by any query that asks for it, it can be populated by an INSERT statement that references it, but you won't see it otherwise.For example, let's start with a simple two column table:ops$tkyte%ORA12CR1> create table t  2  ( x int,  3    y int  4  )  5  /Table created.ops$tkyte%ORA12CR1> insert into t values ( 1, 2 );1 row created.Now, we will add an invisible column to it:ops$tkyte%ORA12CR1> alter table t add                     ( z int INVISIBLE );Table altered.Notice that a DESCRIBE will not show us this column:ops$tkyte%ORA12CR1> desc t Name              Null?    Type ----------------- -------- ------------ X                          NUMBER(38) Y                          NUMBER(38)and existing inserts are unaffected by it:ops$tkyte%ORA12CR1> insert into t values ( 3, 4 );1 row created.A SELECT * won't see it either:ops$tkyte%ORA12CR1> select * from t;         X          Y---------- ----------         1          2         3          4But we have full access to it (in well written programs! The ones that use a column list in the insert and select - never relying on "defaults":ops$tkyte%ORA12CR1> insert into t (x,y,z)                         values ( 5,6,7 );1 row created.ops$tkyte%ORA12CR1> select x, y, z from t;         X          Y          Z---------- ---------- ----------         1          2         3          4         5          6          7and when we are sure that we are ready to go with this column, we can just modify it:ops$tkyte%ORA12CR1> alter table t modify z visible;Table altered.ops$tkyte%ORA12CR1> select * from t;         X          Y          Z---------- ---------- ----------         1          2         3          4         5          6          7I will say that a better approach to this - one that is available in 11gR2 and above - would be to use editioning views (part of Edition Based Redefinition - EBR ).  I would rather use EBR over this approach, but in an environment where EBR is not being used, or the editioning views are not in place, this will achieve much the same.Read these for information on EBR:http://www.oracle.com/technetwork/issue-archive/2010/10-jan/o10asktom-172777.htmlhttp://www.oracle.com/technetwork/issue-archive/2010/10-mar/o20asktom-098897.htmlhttp://www.oracle.com/technetwork/issue-archive/2010/10-may/o30asktom-082672.html

    Read the article

< Previous Page | 213 214 215 216 217 218 219 220 221 222 223 224  | Next Page >