World: r3wp
[SQLite] C library embeddable DB .
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Pekr 16-Mar-2006 [213x2] | ah, now I see ... and I have questions .... Ashley, when the sql query is not block, but a string - you send the query as-is? Why the difference? with ' it works, with " it does not ... can the functionality be made just the same? I think most ppl are used to "quote" string, not to 'quote it like that' .... I would prefer driver to return an error for quotes, if they can't be used, instead of returning string as a word :-) |
it is inconsistent with: sql ["insert into test values (1, ?, ?)" "Petr" "Krenzelok"] ; in this case it returns strings, not words ... imo string and block sql queries should be compatible | |
Oldes 16-Mar-2006 [215] | It should return always string! |
Pekr 16-Mar-2006 [216x3] | there is imo inconsistency between block and string format of query - if you use quotes with block format, it remains string, if you use quotes inside of string query, sqlite returns different values, because a word is returned ... imo there is bug in parsing and in the insert phase with string query format already ... |
uhm, there is no parse inside sqlite.r ;-) either string? statement [statement][first statement] so it may as well be sqlite library, who is causing it .... | |
hehe, type? 'aaaaa'' == word! .... of a value aaaaa' | |
Robert 16-Mar-2006 [219] | It could be a memory alignment problem as well. Maybe some kind of internal offset that gets screwed up. |
Graham 16-Mar-2006 [220] | I'm not following this , but in sql ' is used as the quote character for literal strings, not " |
Pekr 16-Mar-2006 [221] | Graham - you may be right, but anyway, I would like to get even ' quoted chars returned back as a string to rebol, not a words ... |
JaimeVargas 16-Mar-2006 [222x2] | type?/word returns word! |
type? returns datatype! | |
Ashley 16-Mar-2006 [224x2] | Pekr, for an explanation of string vs block see the "Using the Driver" section of: http://www.dobeash.com/SQLite/DriverGuide/ The various refinements (including /direct) are covered earlier in the document under "Database access functions". Jaime: the type? change relates to a problem with "type? ... switch ... #[datatype ..." vs "type?/word ... switch ... integer! ..." as the first form is not compatible with encap. |
Hmm, adding /direct to the example posted previously and changing the last part of the INSERT to "... form $1 1 form $1 * 1" seems to work properly (100 error-free runs so far). The *only* difference then is in this line of the value binding logic: unless direct [val: mold/all val] which if you change it to something like: unless direct [p: mold/all val] *bind-text sid i p length? p 0 seems to handle more runs before a failure. Thinking that mold/all might be the problem I then reran my /direct test with the following SQL statement: SQL reduce ["insert into t values (?,?,?,?,?)" 1 mold/all reform ["A" 1] mold/all $1 1 mold/all $1 * 1] which is functionally equivalent to the failing statement ... but no failures (after 100 runs). So, the conditions needed to reproduce this error [so far] are: SQLite library INSERT statement using a particular sequence of bind variables MOLD/ALL coded / used in a particular manner High volume of INSERTs Now is that an obscure error or what? ;) | |
Pekr 17-Mar-2006 [226] | Ashley - I am not saying anything. I just want consistent result for those two cases - inserting a string into database in the same way, should return the same results .... |
Ashley 17-Mar-2006 [227] | But they are not the same way ... SQL "insert into t values ('text') SQL {insert into t values ('"text"')} map to: SQL ["insert into t values (?)" "text"] ; with /direct refinement SQL ["insert into t values (?)" "text"] ; without /direct refinement The first approach in each case is saying, "I want this value to be stored as a SQLite TEXT value which will not be LOADed upon retrieval"; while the second is saying, "I want this value to be stored as a MOLDed SQLite TEXT value which will be LOADed upon retrieval back into a REBOL string value (as opposed to the word 'text)". A string! statement is strictly literal, it is passed onto SQLite with no parsing or conversion. If you want to bind values, use the block form ... that's what it's there for! |
Pekr 17-Mar-2006 [228x3] | But simply put - string is a string and in rebol I expect a string without the compromises or clumsy /direct refinement .... no wonder person I know remains with sqlite3 driver just because of that ... |
I wonder if /direct is usefull at all and if we should have two modes .... does mysql driver has two modes? | |
and if I, and another person, independently run into problems agains what naturaly ppl would expect without checking docs and study some modes, then there is something wrong. Imo it is the same, as rebol shares subobjects by default - nearly EVERY person I know, run at some problems because of that. Of course it is by some purpose, but then some things are not of "rebol is simiple" nature ... | |
Ashley 18-Mar-2006 [231] | It's simply about choice. By default the driver assumes you want to be dealing with the full range of REBOL datatypes. If all you need are the five datatypes that SQLite supports (Integer, Decimal, Binary, Text and Null) then use the /direct refinement. How is this "confusing" or "clumsy"? If you don't like the fact that the string! form differs from the block form then choose the one you are most comfortable with and stick with that. |
Pekr 18-Mar-2006 [232] | ok, not sure now and I will retest, but the problem also is, that the string form allows you to use "text here" in quotes instead of 'text here' ...but - once you query your db, driver returns it as two separate words because of space - it simply ruins the block, because you get two elements instead of one. Bobik told me, that sqlite3 does not do that, so I assume it is a difference of how returned data is being processed. But I will do some tests using both drivers, because he defined his dbs using some external tool (sqlite admin or so ...) |
Ashley 18-Mar-2006 [233] | You'll find the exact same behaviour with the other sqlite3 scripts ... none of them attempt to parse a literal statement string. The other scripts basically default to /direct which means that any non-numeric / binary values are converted to TEXT (i.e. you can insert a REBOL date! but it comes back as a string!). If you want that behaviour then just use /direct. It's not that complex, really ... |
Graham 20-Mar-2006 [234x3] | Does sqlite support timestamp/date fields ? Is there a way to set a default value for a field ( so that on a sql insert, you don't have to explicitly mention that column ) ? |
Are there any triggers ? | |
Or, autoincrementing fields ? | |
Pekr 20-Mar-2006 [237x2] | Triggers, Views, auto-increments - yes .... (not sure about auto-increments, but iirc yes) |
default value - yes ... | |
Ashley 20-Mar-2006 [239x3] | Graham, yes to all the above except timestamp/date fields. SQLite only supports 5 datatypes: Integer, Decimal, Binary, Null and Text. The driver (unless using the /direct refinement to connect) MOLDs and LOADs other REBOL types such as date!, pair!, etc into SQLite TEXT fields so date is certainly supported at the REBOL level (although an "order by date" clause will not give the expected results ... I tend to use 'sort/skip SQL "select id,date from t" 2' type constructs to achieve the desired result). Given how common this later operation is (order by date) I'm looking at changing the way date is bound. Instead of just MOLDing it, if it is transformed to YYYY-MM-DD format then not only can LOAD recognize it but it can be sorted (as TEXT) directly by SQLite. |
The change to handle date properly is pretty simple in fact (starting at line#375): unless direct [ val: either date? val [ p: reform [val/year val/month val/day] all [val/month < 10 insert skip p 5 "0"] all [val/day < 10 insert skip p 8 "0"] poke p 5 #"/" poke p 8 #"/" p ] [mold/all val] ] | |
The only question is which delimiters do folks prefer? "-" "/" "." or ":" | |
Graham 20-Mar-2006 [242x3] | why not change dates into gregorian values ? |
what do the unix people use? | |
also, this doesn't handle date stamps with time/seconds. | |
Ashley 21-Mar-2006 [245] | gregorian values ... what's the format mask for that? |
Graham 21-Mar-2006 [246x2] | this is now in unix timestamp 1142917662 |
oops, I think I meant Julian day numbers. | |
Pekr 21-Mar-2006 [248x2] | In Dbase, the date was stored in db in YYYYMMDD, so I vote for the date storage change too ... really helps sorting ... |
Ashley - the question is, if there should be any delimiter in DB :-) You can write simple copy/part at .... if you want .... and load will load it into rebol format anyway, no? | |
Graham 21-Mar-2006 [250] | If they are stored as numbers, then just as easy to sort! |
sqlab 21-Mar-2006 [251] | YYYYMMDD is the short form of the iso date, otherwise it should be YYYY-MM-DD, if I remember. |
Pekr 21-Mar-2006 [252] | hmm, DBase tools have it like I said - YYYYMMDD, and it is question of date mask (which can be set upon locale, which rebol does not support :-), if you use dot, slash, whatever as a separator ... |
Graham 21-Mar-2006 [253] | what about time?? |
Pekr 21-Mar-2006 [254] | iirc dbase does not support time datatype ... |
Graham 21-Mar-2006 [255] | I meant I'd like to see a full timestamp datatype support. |
sqlab 21-Mar-2006 [256x2] | it's also covered by ISO 8601 YYYY-MM-DD hh:mm:ss or compact YYYYMMDDhhmmss I use mostly the compact form in my scripts. |
If it's not for human communication, the space between date und time is a T so now /precise is 2006-03-21T11:06:48.232+01 | |
Pekr 21-Mar-2006 [258] | but it is easy to convert to - replace time-value "T" " " " :-) |
sqlab 21-Mar-2006 [259] | It is easier for the console parser |
JaimeVargas 21-Mar-2006 [260] | In unix the time is expressed in seconds and microseconds since midnight (0 hour), January 1, 1970. The resolution of the system clock is hardware dependent, and the time may be updated continuously or in ``ticks.'' The following structures are defined in <sys/time.h> as: struct timeval { long tv_sec; /* seconds since Jan. 1, 1970 */ long tv_usec; /* and microseconds */ }; struct timezone { int tz_minuteswest; /* of Greenwich */ int tz_dsttime; /* type of dst correction to apply */ }; The timezone structure indicates the local time zone (measured in minutes of time westward from Greenwich), and a flag that, if nonzero, indicates that Daylight Saving time applies locally during the appropriate part of the year. |
Sunanda 21-Mar-2006 [261] | Worth noting that they are UNIX seconds not UTC seconds.....UNIX time does not recognise leap seconds, so it's now seven (I think) seconds adrift. http://en.wikipedia.org/wiki/Unix_time |
JaimeVargas 21-Mar-2006 [262] | Indeed, However I think the timezone files can be used to do the adjustment if desired, and this may happen in the future. |
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