difference between IS NULL and = NULL

Hello guys,.

10 gr 2, what is the difference between IS NULL and = NULL

Thank you
Imran

NULL is not equal to zero or a specific value
NULL means unknown

the first form will work, given that the value of a field may be unknown (= IS NULL)

the other will not work, because a specific value is not equal to unknown
the first is the correct form, the second will always be false
same NULL = NULL can be distorted, because unknown is unknown

Tags: Database

Similar Questions

  • Difference between v$ session and v$ _session

    Please say it.

    (1) difference between v$ session and v$ _session

    (2) v$ session a synonym, derived from v$ _session or v$ _session is views v$ session... hw are created and interlinked

    1 V_$ SESSION and GV_$ SESSION are seen, where as GV$ SESSION and V$ SESSION are synonymous: -.

    07:17:43 oracle[SQLPLUS]@dbalnp01[fraespappp90c] > select * dict where TABLE_NAME in (' V$ SESSION ', ' GV$ SESSION ");

    TABLE_NAME COMMENTS
    ------------------------------ --------------------------------------------------------
    Synonym SESSION GV$ for GV_$ SESSION
    V$ SESSION synonym of V_$ SESSION

    [06: 53:14 oracle[SQLPLUS]@dbalnp01[fraespappp90c] > select owner, object_name, object_type, status, CREATED, LAST_DDL_TIME from dba_objects where in('V_$SESSION','GV_$SESSION','GV$SESSION','V$SESSION') object_name.

    STATUS OF OWNER CREATED LAST_DDL_TIME OBJECT_TYPE OBJECT_NAME
    ------------------------------ ------------------------------ ------------------- ------- ----------------- -----------------
    SYS GV_$ SESSION VIEW VALID 20100329 08:45:36 20100329 08:45:36
    SYS V_$ SESSION VIEW VALID 20100329 08:45:27 20100329 08:45:27
    SYNONYM OF SGS PUBLIC SESSION $ VALID 20100329 08:45:36 20100329 08:45:36
    PUBLIC SYNONYM V$ SESSION VALID 20100329 08:45:27 20100329 08:45:27

    [06: 51:12 oracle[SQLPLUS]@dbalnp01[fraespappp90c] > select OWNER, SYNONYM_NAME, TABLE_OWNER, TABLE_NAME from dba_synonyms where SYNONYM_NAME like 'V_SESSION ';

    OWNER SYNONYM_NAME TABLE_OWNER, TABLE_NAME
    ------------------------------ ------------------------------ ------------------------------ ------------------------------
    PUBLIC V$ SESSION SYS V_$ SESSION

    [06: 51:20 oracle[SQLPLUS]@dbalnp01[fraespappp90c] > select OWNER, SYNONYM_NAME, TABLE_OWNER, TABLE_NAME from dba_synonyms where SYNONYM_NAME like 'GV_SESSION ';

    OWNER SYNONYM_NAME TABLE_OWNER, TABLE_NAME
    ------------------------------ ------------------------------ ------------------------------ ------------------------------
    OPEN SGS MEETING $ SYS GV_$

    07:17:24 oracle[SQLPLUS]@dbalnp01[fraespappp90c] > select VIEW_NAME, dba_views TEXT where VIEW_NAME in('GV_$SESSION','V_$SESSION');

    VIEW_NAME TEXT
    ------------------------------ --------------------------------------------------------------------------------
    Gv_$ SESSION select INST_ID 'select', 'SADDR', 'SID', ' SERIAL # ', 'AUDSID', 'PADDR', ' USER # ","USERNAME","CO ".
    "MM AND ', 'OWNERID', 'TADDR', 'LOCKWAIT', 'STATUS', 'SERVER', ' SCHEMA #", "SCHEMANAME", "OS".
    USER', 'PROCESS', 'MACHINE', 'TERMINAL', 'PROGRAM', 'TYPE', 'SQL_ADDRESS', 'SQL_HASH_VA '.
    READ', 'SQL_ID', 'SQL_CHILD_NUMBER', 'PREV_SQL_ADDR', 'PREV_HASH_VALUE', 'PREV_SQL_ID '.
    , 'PREV_CHILD_NUMBER', 'PLSQL_ENTRY_OBJECT_ID', 'PLSQL_ENTRY_SUBPROGRAM_ID', 'PLSQL_ '.
    "OBJECT_ID", 'PLSQL_SUBPROGRAM_ID', 'MODULE', 'MODULE_HASH', 'ACTION', "ACTION_HASH '"
    CLIENT_INFO","FIXED_TABLE_SEQUENCE"," ROW_WAIT_OBJ # "," ROW_WAIT_FILE # ","ROW_WAIT_B ".
    "LOCK #", "ROW_WAIT_ROW #", "LOGON_TIME', 'LAST_CALL_ET', 'PDML_ENABLED', 'FAILOVER_TYPE '.
    ', 'FAILOVER_METHOD', 'FAILED_OVER', 'RESOURCE_CONSUMER_GROUP', 'PDML_STATUS', 'PDDL_ '.
    STATUS', 'PQ_STATUS', 'CURRENT_QUEUE_DURATION', 'CLIENT_IDENTIFIER', 'BLOCKING_SESSI '.
    ON_STATUS', 'BLOCKING_INSTANCE', 'BLOCKING_SESSION', ' SEQ # ', ' EVENT # ', 'EVENT', 'P1TEX '.
    "T", "P1", 'P1RAW', 'P2TEXT', 'P2', 'P2RAW', 'P3TEXT', 'P3', 'P3RAW', 'WAIT_CLASS_ID', 'WAI '.
    "T_CLASS #", "WAIT_CLASS", "WAIT_TIME', 'SECONDS_IN_WAIT', 'STATE', 'SERVICE_NAME', 'SQL '.
    _TRACE', 'SQL_TRACE_WAITS', 'SQL_TRACE_BINDS' of gv$ session

    V_$ SESSION select "SADDR", "SID", "SERIAL #", "AUDSID", 'PADDR', ' USER # ', 'USERNAME', 'ORDER', 'OW. '
    NERID', 'TADDR', 'LOCKWAIT', 'STATUS', 'SERVER', ' SCHEMA # ","SCHEMANAME", 'OSUSER', 'PRO '.
    CESS', 'MACHINE', 'TERMINAL', 'PROGRAM', 'TYPE', 'SQL_ADDRESS', 'SQL_HASH_VALUE', 'SQL_ '.
    "ID", "SQL_CHILD_NUMBER", "PREV_SQL_ADDR", "PREV_HASH_VALUE", "PREV_SQL_ID", "PREV_CHI".
    LD_NUMBER', 'PLSQL_ENTRY_OBJECT_ID', 'PLSQL_ENTRY_SUBPROGRAM_ID', 'PLSQL_OBJECT_ID '.
    , 'PLSQL_SUBPROGRAM_ID', 'MODULE', 'MODULE_HASH', 'ACTION', 'ACTION_HASH', 'CLIENT_INF '.
    O","FIXED_TABLE_SEQUENCE"," ROW_WAIT_OBJ # "," ROW_WAIT_FILE # "," ROW_WAIT_BLOCK # ","RO ".
    "W_WAIT_ROW #", "LOGON_TIME', 'LAST_CALL_ET', 'PDML_ENABLED', 'FAILOVER_TYPE', 'FAILOVE.
    R_METHOD', 'FAILED_OVER', 'RESOURCE_CONSUMER_GROUP', 'PDML_STATUS', 'PDDL_STATUS', 'P '.
    Q_STATUS', 'CURRENT_QUEUE_DURATION', 'CLIENT_IDENTIFIER', 'BLOCKING_SESSION_STATUS '.
    , 'BLOCKING_INSTANCE', 'BLOCKING_SESSION', ' SEQ # ', ' EVENT # ', 'EVENT', 'P1TEXT', 'P1', 'P '.
    1RAW', 'P2TEXT', 'P2', 'P2RAW', 'P3TEXT', 'P3', 'P3RAW', 'WAIT_CLASS_ID', ' WAIT_CLASS, #
    'WAIT_CLASS', 'WAIT_TIME', 'SECONDS_IN_WAIT', 'STATE', 'SERVICE_NAME', 'SQL_TRACE","S
    QL_TRACE_WAITS","SQL_TRACE_BINDS"from v$ session

    Definition of GV$ SESSION and V$ SESSION;

    [07: 25:29 oracle[SQLPLUS]@dbalnp01[fraespappp90c] > select definition_de_vue from v$ fixed_view_definition where view_name = "GV$ SESSION;

    DEFINITION_DE_VUE
    --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
    select s.inst_id,s.addr,s.indx,s.ksuseser,s.ksuudses,s.ksusepro,s.ksuudlui,s.ksuudlna,s.ksuudoct,s.ksusesow, decode(s.ksusetrn,hextoraw('00'),null,s.ksusetrn),decode(s.ksqpswat,hextoraw('00'),null,s.ksqpswat),decode(bitand(s.ksuseidl,11),1,'ACTIVE',0,decode(bitand(s.ksuseflg,4096),0,'INACTIVE','CACHED'),2,'SNIPED',3,'SNIPED', 'KILLED'),decode(s.ksspatyp,1,'DEDICATED',2,'SHARED',3,'PSEUDO','NONE'), s.ksuudsid,s.ksuudsna,s.ksuseunm,s.ksusepid,s.ksusemnm,s.ksusetid,s.ksusepnm, decode(bitand(s.ksuseflg 19) , 17, 'BACKGROUND', 1, 'USER', 2, 'RECURSIVE','? '), s.ksus
    ESQL, s.ksusesqh, s.ksusesqi, decode (s.ksusesch, 65535, to_number (null), s.ksusesch), s.ksusepsq, s.ksusepha, s.ksusepsi, decode (s.ksusepch, 65535, to_number (null), s.ksusepch), decode (s.ksusepeo, 0, to_number (null), s.ksusepeo), decode (s.ksusepeo, 0, to_number (null), s.ksusepes), decode (s.ksusepco, 0, to_number (null), s.ksusepco), decode (s.ksusepco, 0, to_number (null), s.ksusepcs), s.ksuseapp, s.ksuseaph, s.ksuseact, s.ksuseach, s.ksusecli, s.ksusefix, s.ksuseobj, s.ksusefil, s.ksuseblk, s.ksuseslt, s.ksuseltm, s.ksusectm, decode (bitand (s.ksusepxopt 12) 0, ' N
    O','YES'),decode(s.ksuseft, 2,'SESSION', 4,'SELECT',8,'TRANSACTIONAL','NONE'),decode(s.ksusefm,1,'BASIC',2,'PRECONNECT',4,'PREPARSE','NONE'),decode(s.ksusefs, 1, 'YES', 'NO'),s.ksusegrp,decode(bitand(s.ksusepxopt,4),4,'ENABLED',decode(bitand(s.ksusepxopt,8),8,'FORCED','DISABLED')),decode(bitand(s.ksusepxopt,2),2,'FORCED',decode(bitand(s.ksusepxopt,1),1,'DISABLED','ENABLED')),decode(bitand(s.ksusepxopt,32),32,'FORCED',decode(bitand(s.ksusepxopt 16) ((, 16, 'DISABLED', 'ENABLED')), s.ksusecqd, s.ksuseclid, decode (s.ksuseblocker, 4294967295, "UNKNOWN", 4294967294)
    ('UNKNOWN', 4294967293, 4294967292 'UNKNOWN', 'No. HOLDER', 4294967291, 'NOT IN WAIT', 'VALID'), decode (s.ksuseblocker, 4294967295, to_number (null), 4294967294, to_number (null), 4294967293, to_number (null), 4294967292, to_number (null), 4294967291, to_number (null), bitand(s.ksuseblocker, 2147418112)/65536), decode (s.ksuseblocker, 4294967295, to_number (null), 4294967294, to_number (null), 4294967293, to_number (null), 4294967292, to_number (null), 4294967291, to_number (null), bitand (s.ksuseblocker) 65535)), s.ksuseseq, s.ksuseopc, e.kslednam, e.ksledp1, s.ksusep1, s.ksusep1r, e.ks
    ledp2, s.ksusep2, s.ksusep2r, e.ksledp3, s.ksusep3, s.ksusep3r, e.ksledclassid, e.ksledclass #, e.ksledclass, decode (s.ksusetim, 0, 0,-1, -1, -2-2, decode(round(s.ksusetim/10000),0,-1,round(s.ksusetim/10000))), s.ksusewtm, decode (s.ksusetim, 0, "PENDING",-2, 'TIME WAITED UNKNOWN', -1, 'WAITED SHORT TIME', decode (round (s.ksusetim/10000), 0, 'WHEREAS SHORT TIME', 'WHEREAS KNOWN TIME')), s.ksusesvc, decode (bitand(s.ksuseflg2,32), 32, 'ENABLED', 'DISABLED'), (bitand (s.ksuseflg2 decode (, (64) 64, "TRUE", "FALSE"), decode (bitand (s.ksuseflg2, 128), 128, "TRUE", "FALSE") x $ ksuse s, x
    e $ksled where bitand (s.ksspaflg, 1). = 0 and bitand (s.ksuseflg, 1). = 0 and s.ksuseopc = e.indx

    [07: 27:25 oracle[SQLPLUS]@dbalnp01[fraespappp90c] > select definition_de_vue from v$ fixed_view_definition where view_name = "V$ SESSION;

    DEFINITION_DE_VUE
    --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
    Select SADDR, SID, SERIAL #, AUDSID, PADDR, USER #, USER name, COMMAND, OWNERID, TADDR, LOCKWAIT, STATUS, SERVER, SCHEMA #, SCHEMANAME, OSUSER, PROCESS, MACHINE, TERMINAL, PROGRAM, TYPE, SQL_ADDRESS, SQL_HASH_VALUE, SQL_ID, SQL_CHILD_NUMBER, PREV_SQL_ADDR, PREV_HASH_VALUE, PREV_SQL_ID, PREV_CHILD_NUMBER, PLSQL_ENTRY_OBJECT_ID, PLSQL_ENTRY_SUBPROGRAM_ID, PLSQL_OBJECT_ID, PLSQL_SUBPROGRAM_ID, MODULE, MODULE_HASH , ACTION, ACTION_HASH, CLIENT_INFO, FIXED_TABLE_SEQUENCE, ROW_WAIT_OBJ #, ROW_WAIT_FILE #, ROW_WAIT_BLOCK #, ROW_WAIT_RO
    W #, LOGON_TIME, LAST_CALL_ET, PDML_ENABLED, FAILOVER_TYPE, FAILOVER_METHOD, FAILED_OVER, RESOURCE_CONSUMER_GROUP, PDML_STATUS, PDDL_STATUS, PQ_STATUS, CURRENT_QUEUE_DURATION, CLIENT_IDENTIFIER, BLOCKING_SESSION_STATUS, BLOCKING_INSTANCE, BLOCKING_SESSION, SEQ #, EVENT #, EVENT, P1TEXT, P1, P1RAW, P2TEXT, P2, P2RAW, P3TEXT, P3, P3RAW, WAIT_CLASS_ID, WAIT_CLASS #, WAIT_CLASS, WAIT_TIME, SECONDS_IN_WAIT, STATE, SERVICE_NAME , SQL_TRACE, SQL_TRACE_WAITS, SQL_TRACE_BINDS of GV$ SESSION where INST_ID select = USERENV ('Instance')

    [07: 27:47 oracle[SQLPLUS]@dbalnp01[fraespappp90c] >

    x$ ksled $ksuse and x are fixed tables for GV$ SESSION.

    I hope it is clear now.

  • Difference between the message and conversation

    What is the technical difference between a message and a conversation. Is that when multiple messages are in 1 conversation?

    A message.
    An email received or sent is a message.

    A conversation can be launched with a message.
    A conversaion can have messages, screw where the example: the 'Reply' button was used and enamel is spent here and there with the comments.

    If you select multiple messages in a list, they will be displayed below in the Message pane in the form xx number of conversatons.

    If you right-click on a message in the list and choose "open in a conversation." then it will open in a new tab showing all the emails included threaded, which are relevant to that conversation, both received emails and those you sent.

  • What is the difference between the password and access code

    I get all the IDs and passwords and none are accepted

    "I received message' iPad requires your password after restart", but it does not accept passwords

    What is the difference between the password and access code

    Standard codes which block the iPad are 4 or 6-digit. You can set a more difficult to decode, personalized access code / password in the settings using letter and numbers if you wish.

    A password is a series of numbers, symbols and letters that a user putting in place to protect the information in a frame, a web site, e-mail, etc. This may actually be a word or series of words, if you wanted to set up in this way.

    Your iPad is looking for this 4- or 6-digit code. If you can remember, you must restore the device so for free.

    If you have forgotten the password for your iPhone, iPad or iPod touch, or your device is disabled - Apple supports

  • Difference between Portege R700 and Satellite R630

    What is the difference between the two models, Portege R700 and Satellite R630?
    Is it only fingerprint, port dock station reader and a more powerful configuration (CPU, SSD, WiFi 802.11n, Type)?
    Is this the same materials used body? Is it the same weight?

    I found this comparison:
    [http://www.ultra-laptops.com/comparisons/toshiba_portege_r700-s1330_vs_toshiba_satellite_r630-131]

    Hi snicker_1,

    There are many differences between these models and also, there are different R700 and R630 models on the market.

    In my opinion, you should check these notebooks from Toshiba Web site. There you can see what models are currently available and the configuration.

    Satellite R630 page:
    http://EU.computers.Toshiba-Europe.com/innovation/generic/B2C-satellite-R630

    Portege R700 page:
    http://EU.computers.Toshiba-Europe.com/innovation/generic/B2B-Portege-R700

  • Difference between the G20 and G25 models

    Hi people!

    I searched your laptop and I was amazed by the Qosmio.
    When I was going to order it, I noticed that there are many models of the G20 with different specifications. Also, I found G25 on internet research and found no difference between the G25 and G20 except receiver TV G25 is NTSC and G20 was released on March and G25 was in June. Instead, they have the same specifications for the hard drive.

    I live in the Portugal and the model Qosmio I can find that this is the G20-118. I was looking for the model that has 2 x 100 GB SATA HD, but cannot not thought about it.

    Internet research I found Qosmio G20-111 which has 2 x 100 GB SATA HD, but on the web page mentioned that it was a Pentium III processor (ridiculous, isn't?). I was looking for more reliable information.

    Already searched for toshiba pages and found no specifications for all models I found 490LS on the research on the web as the G20 - 102, 105, 106, 108, 109, 111, 118, 123,...

    Can someone help me with this? Are there any reliable web page where I can see the differences between the models? is there a .pdf or anyone who can please give me some advice?

    Money is not a problem at this time to acquire the laptop, I'm looking for only the laptop performance more!

    Best regards
    João Pereira

    Hello

    It of very difficult to say what camera is best, because there are many models with different parts.
    However, I found page with description of the G20 and G25.
    Take a look at this link.

    http://www.releasereview.com/Toshiba-Qosmio-G20-105-108-114.aspx?d=0101000580926052005

    Good bye

  • What is the difference between the iwatcha and the Apple Watch?

    What is the difference between the iwatch and Apple Watch?  In the sales pitch pre for the iwatch, the price was given to about $17,000, while the Apple Watch sells in the $350-500 range. What gives?

    There is no such thing as a iWatch.

    There are three versions of the Apple Watch.

    Apple Watch Sport

    Apple Watch

    Apple Watch Edition

    https://www.Apple.com/watch/buy/

  • Jack screw part number clarification: difference between 187949-01 and 187949-10

    We bought a few jack live, Mfr P/N 187949-10, but the parts are labeled 187949-01. What is the difference between-10 and -01. Are parts of the same, but differ only in the amount of packaging? Thank you.

    Hi Mwong,

    Thanks for the post and I hope that your well today - welcome to the Forums of NOR.

    I'm sorry to see that you have not yet received any support.

    Looking at the site, ni.com, here, I found this information,

    Specifications and manufacturers for Council mating of connectors

    http://digital.NI.com/public.nsf/allkb/8ECF4BAD615F18BC8625648400521E97

    (1) 4 piece Kit of screws for connection cables 187949-01 locking screw

    (10) 4 piece Kit of screws for connection cables 187949-10 locking screw

    That is why the differences between the 01 and 10 is the number of kits.

    However the link here.

    Specifications and Dimensions of the female connectors to screws used on 68 pins plug-in connectors

    http://digital.NI.com/public.nsf/allkb/43771DBD89FADB7B86256BC90053EC08

    "The kit contains 40 screws and washers (enough to convert the two ends of the).
    10 sets of cables). The part number of the kit is 187949-01 "

    But I guess that goes back to were you waiting for 1 or 10 sets?

    I hope this helps.

  • geometric matching: difference between the scores and correlation

    Hi all

    What is the difference between the scores and correlation in geometric correspondence?

    Hello

    the correlation score is based on pixel intensities while the score of the geometric game also considers the characteristics of the geometry. See the Concepts of Vision or (geometric matching-> discussion).

    I hope this helps.

    Best regards

    K

  • What is the difference between the IO and line?

    Hi all

    I'm using Labview 7 and in my mahcine I have an installed 6013 card. However, there was an interface card designed by someone else long ago, on the table, only AO0, AO1,..., A07, DIO0, DIO1,..., DIO7 were printed. In the program, I saw some code to write to digital Line.vi allows you to send data to the digial io. Say that I write for DIO 3, so I understand here DIO 3 means the channel of e/s 3, but online? What is the difference between the channel and the line? When I write the data to a single channel of e/s, are us wriitng a byte or a bit of it? Thank you.

    A channel is usually used with inputs/outputs analog.  Each AI or AO is a string.

  • 8.5.1 LabVIEW Student Edition - differences between the Mac and Windows versions?

    Hello

    I just bought the student of LabVIEW 8.5.1 version and I use Mac OS X 10.4.11. What are the biggest differences between the Mac and Windows versions, since the box came with a CD of installation of Mac and a Windows DVD Installer?

    See you soon

    Looks like you got the LabVIEW Student Edition Software Suite DVD.

    It comes with 6 boxes to tools, and the TME product, some (or all?) of those who are windows only (at least 8.5), for example:

    • Toolkit Digital Filter Design
    • Modulation Toolkit
    • SignalExpress
    • ...

    Since you have 8.5, you are missing also a few basic things that only recevied at the 8.6MAC support, like Mathscript, Control design and Simulation and native 3D graphics.

  • Major difference between the Group and the organizational unit?

    Pls explain me what is the difference between the groups and the organization unit in simple terms with an example in real time.

    Hello

    https://en.Wikipedia.org/wiki/Organizational_unit _ (computing)

    https://en.Wikipedia.org/wiki/Group _ (computing)

    See you soon.

  • What are the differences between the services and site domain group policy and group policy?

    What are the differences between the services and site domain group policy and group policy?

    Server must wonder about the Technet site.  http://social.technet.Microsoft.com/forums/en-us/home

  • There are the functional differences between the trial and the full version?

    There are the functional differences between the trial and the paid version for Labview 2009?  Thank you.

    He described the Labview eval version limitations: Limitations of the Evaluation Version of LabVIEW

    See you soon,.

  • What is the difference between HP Envy and HP Pavilion?

    Which is better and why?

    Hello

    Feel like machines are much bettr built and care generally superior to her ===> higher prices. A lot of people asking the same question such as:

    http://Forum.NotebookReview.com/threads/envy-vs-Pavillion.669607/

    http://h30434.www3.HP.com/T5/other-notebook-PC-questions/help-with-the-difference-between-the-envy-and-Pavilion/TD-p/2289959

    they are also designed to compete with other lines to other providers. Please read more information:

    http://en.Wikipedia.org/wiki/HP_Pavilion_%28computer%29

    http://en.Wikipedia.org/wiki/HP_Envy

    Kind regards.

Maybe you are looking for