I'm currently trying to connect my R session to a MySQL server using the RMySQL package.
One of the tables on the server is called "order", I already searched how you can import a table called order with MySQL (by putting it into ''), yet the syntax does not work for the RMySQL query.
when I run the following statement:
order_query = dbSendQuery(mydb,"SELECT * FROM 'order'")
It returns the following error:
Error in .local(conn, statement, ...) : could not run statement:
You have an error in your SQL syntax; check the manual that
corresponds to your MySQL server version for the right syntax to use
near ''order'' at line 1
Anyone knows how to get around this in R?
Single quotes in MySQL indicate string literals, and you should not be putting them around your table names. Try the query without the quotes:
order_query = dbSendQuery(mydb,"SELECT * FROM `order`")
If you did, for some reason, need to escape your table name, then use backticks, e.g.
SELECT * FROM `some table` -- table name with a space (generally a bad thing)
Edit:
As #Ralf pointed out, in this case you do need backticks because ORDER is a MySQL keyword and you should not be using it to name your tables and columns.
Related
I am a completely new to SQL and I am follow a tutorial verbatim to try and create a new table in my first database. However I am getting the following error.
USE menu;
CREATE TABLE Burgers
(
`Burger Number` TINYINT,
Burger VARCHAR(50),
Price DECIMAL(5,2),
Description VARCHAR(300),
);
Yields SQL Error 1064:
SQL Error (1064): You have an errror in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near ')' at line 8
I made sure to use commas to separate each column and used parenthesis to what I understand is the proper way to do so. I am not sure if version is relevant but I am using version 10.5.8 of MariaDB. Any insight is appreciated!
You have one comma too many.
...
Description VARCHAR(300),
);
You need commas between each column, index, or constraint within the CREATE TABLE statement, except for the last one before the closing parenthesis.
It should be like this:
...
Description VARCHAR(300)
);
General tip about syntax errors: They tell you exactly where to look for the problem, because it reports the place in your SQL statement where the syntax parser got confused.
In this case it reported:
...right syntax to use near ')' at line 8
This tells you the problem is at that point in the syntax. The ) didn't belong there, because the syntax was expecting something else. Because commas separate columns, it was expecting another column definition following a comma.
Consider this:
> scr<-paste("INSERT INTO ques2_log (freeze_time) value(",sQuote(now()),")")
> scr
#> "INSERT INTO ques2_log (freeze_time) value( ‘2017-06-13 23:46:16’ )"
If we feed this simple SQL script into a MySQL DB as follows:
dbExecute(db,scr1)
The MySQL DB throws the following error:Error in .local(conn, statement, ...) : could not run statement: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '��2017-06-13 23:44:13’ )' at line 1
I have tested the SQL script by typing by hand and it works.
It is also clear that the single quote is the unexpected character.
I looked up some online articles on character encoding and tried
enc2utf8(scr) before feeding to the DB through RMySQL commands. No effect. Same error.
I also read this and ran
ALTER DATABASE ques2_log CHARACTER SET utf8 COLLATE utf8_general_ci;
But the error remains.
Just use regular single quotes, as in:
paste0("'",date(),"'")
sQuote produces distinct left and right "smart" quotes, as documented in ?sQuote:
Single or double quote text by combining with appropriate single or
double left and right quotation marks.
...and additionally, the documentation makes clear that the intended purpose of this function is for formatting text for displaying user facing messages on screen:
The purpose of the functions is to provide a simple means of markup
for quoting text to be used in the R output, e.g., in warnings or
error messages.
So it generally shouldn't be used for processing text to be used programmatically.
Code:
dbWriteTable(con, name=symbol, value=df, row.names=FALSE, append=TRUE)
Error in mysqlExecStatement(conn, statement, ...) :
RS-DBI driver: (could not run statement: You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'SSL
(
Date text,
Open double,
High double,
Low double,
Close double,
Volum' at line 1)
The issue is the ticker symbol "SSL" is also a MySQL keyword. It seems RMySQL is not escaping the table name?
Just to add, same problem with tickers "ALL" and "KEY", also reserved words. So I just need to figure out how to properly escape the table name with RMySQL, but so far am coming up empty.
Edit to add: I realize it is possible to use dbSendQuery but really want to make use of dbWriteTable instead. I am really surprised that the table name is not properly backticked automatically?
Edit to add more: I also tried name=paste0(dbname,".",symbol) for example, which works with MySQL to get past the reserved words, but what I found is that the dbWriteTable function uses the dbExistsTable() function built-in, and that function does not work with the change.
I could rewrite the dbExistsTable function to overwrite built-in as a workaround, but I do not know how to get the dbname from the dbConnect() function to become inherited. Still looking into this...
I'm trying to run a simple query that works with MySQL or other MySQL connector API's,
SELECT * FROM `table` WHERE type = 'farmer'
I've tried various methods using the RMySQL package and they all get the same error
RS-DBI driver warning: (unrecognized MySQL field type 7 in column 1 imported as character)
Type = 'farmer'
(Query<-paste0("SELECT * FROM `table` WHERE type = '%",Type,"%'"))
res<-dbGetQuery(con, Query)
Query<-paste("SELECT * FROM `table` WHERE type = \'farmer\'")
Query<-paste("SELECT * FROM `table` WHERE type = 'farmer'")
What am I doing wrong?
"type" is a keyword in MYSQL. Surround the it with backticks to escape field names.
SELECT * FROM `table` WHERE `type` = 'farmer'
Also you probably have a time stamp column in your table. R is known to not recognize that column type. Convert it to a unix time stamp in the portion of the SQL statement.
Looks like the db schema has something in column which is of type 7 -- and that type appears to be unknown to the RMySQL driver.
I try to exclude column one in the query, or cast it at the select * ... level eg via something like
select foo as character, bar, bim, bom from 'table' where ...
To be clear, when I encountered this error message, it was because my data field was a time stamp.
I verified this by changing my query to SELECT created_at FROM ... which caused the error. I also verified this by changing the query not to include the column names that were timestamps, then I had no errors.
Note too, that the error message counts columns starting from 0 (instead of 1 as R does)
IMHO, the answer is you aren't doing anything wrong, but it's something that needs to be fixed in RMySQL.
The workaround is after you read in your data, you need to call one of the several possible character to datetime conversion functions. (Which one depends on what you want to do with the time stamp exactly.)
I have the following problem and I'm begging for help: I'm using swi-prolog and odbc interface to connect to postgresql database. Problem occurs when I try to insert in database. SELECT works fine but INSERT doesn't work. Does anybody know what am I doing wrong.
Here's my simple test code:
:-use_module(library(odbc)).
connect(C):-
odbc_connect(baza, C, [user(Mat),
password(lozinka), alias(baza), open(once)]).
sel(R) :-
odbc_query(baza,
'SELECT * FROM pacijent',
R).
ins:-
odbc_query(baza, 'INSERT INTO pacijent (name, surname, passw, number) VALUES ("James", "Bond", 007, 007)').
This is the error when i try to insert:
?- ins.
ERROR: ODBC: State S1000: [unixODBC]ERROR: column "James" does not exist at character 30;
Error while executing the query
Also i tried to insert through psql console and everything works fine, but as said problem is when inserting from prolog.
Please help, im stuck here.
Thanks
A suggestion: proper escaping, don't know if it'll be enough though. I'd turn
"James", "Bond"
into
\'James\', \'Bond\'
The problem is you've passed the column data for columns name and surname in double quotes instead of single quotes. Most databases use " (double quotes) for identifiers like table and column names and ' (single quotes) for data. How you ensure that in prolog I don't know.
I suspect you'll want to quote the other 2 columns as well.
In ODBC you'd use SQLGetInfo and get SQL_IDENTIFIER_QUOTE_CHAR which will usually return double quotes meaning to quote identifiers use these quotes.