db: fix some examples
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			@ -271,24 +271,21 @@ ARTICLE: "db-lowlevel-tutorial" "Low-level database tutorial"
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{ $subsections sql-query }
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"Here's an example usage where we'll make a book table, insert some objects, and query them." $nl
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"First, let's set up a custom combinator for using our database. See " { $link "db-custom-database-combinators" } " for more details."
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{ $code """
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USING: db.sqlite db io.files io.files.temp ;
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{ $code """USING: db.sqlite db io.files io.files.temp ;
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: with-book-db ( quot -- )
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    "book.db" temp-file <sqlite-db> swap with-db ; inline" }
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    "book.db" temp-file <sqlite-db> swap with-db ; inline""" }
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"Now let's create the table manually:"
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{ $code " "create table books
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{ $code """"create table books
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    (id integer primary key, title text, author text, date_published timestamp,
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     edition integer, cover_price double, condition text)"
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    [ sql-command ] with-book-db""" }
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"Time to insert some books:"
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{ $code """
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"insert into books
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{ $code """"insert into books
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    (title, author, date_published, edition, cover_price, condition)
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    values('Factor for Sheeple', 'Mister Stacky Pants', date('now'), 1, 13.37, 'mint')"
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[ sql-command ] with-book-db""" }
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"Now let's select the book:"
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{ $code """
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"select id, title, cover_price from books;" [ sql-query ] with-book-db""" }
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{ $code """"select id, title, cover_price from books;" [ sql-query ] with-book-db""" }
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"Notice that the result of this query is a Factor array containing the database rows as arrays of strings. We would have to convert the " { $snippet "cover_price" } " from a string to a number in order to use it in a calculation." $nl
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"In conclusion, this method of accessing a database is supported, but it is fairly low-level and generally specific to a single database. The " { $vocab-link "db.tuples" } " vocabulary is a good alternative to writing SQL by hand." ;
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			@ -298,10 +295,9 @@ ARTICLE: "db-custom-database-combinators" "Custom database combinators"
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"Make a " { $snippet "with-" } " combinator to open and close a database so that resources are not leaked." $nl
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"SQLite example combinator:"
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{ $code """
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USING: db.sqlite db io.files io.files.temp ;
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{ $code """USING: db.sqlite db io.files io.files.temp ;
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: with-sqlite-db ( quot -- )
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    "my-database.db" temp-file <sqlite-db> swap with-db ; inline""" } 
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    "my-database.db" temp-file <sqlite-db> swap with-db ; inline""" }
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"PostgreSQL example combinator:"
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{ $code """USING: db.postgresql db ;
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