50 lines
1.9 KiB
Go
50 lines
1.9 KiB
Go
package oci8
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/*
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Understanding Oracle
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It's a bit different than the other RDBMS databases and I'll just try to
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hightlight a few of the important ones the dialect has to deal with:
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1. Oracle upper cases all non-quoted identifiers. That means the dialect
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has to decide what to do:
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1. quote all identifiers which would require developers to quote every
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identifer they passed in a string to gorm.
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2. only quote identifers that conflict with reserved words and leave all
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other identifiers unquoted, which means Oracle will automatically
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upper case them. This would allow developers to pass unquoted
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identifiers in strings they passed to gorm and make the experience
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align better with the other dialects.
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We chose option #2.
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This design decision has the following side affects:
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a. you must be case insensitive when matching column names, like in
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the Scope.scan function
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b. Devs will have to escape reserved words when they reference them
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in things like: First(&CreditCard{}, `"number" = ?`)
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2. Oracle handles last inserted id a bit differently, and requires a sql.Out
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parameter to return the value in the oci8 driver. Since Oracle parameters
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are positional, you need to know how many other bind variables there are before
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adding the returning clause. We've implemented the
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OraDialect.CreateWithReturningInto(*Scope) to handle this.
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3. Oracle doesn't let you specify "AS <tablename> " when selecting a count
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from a dynamic table, so you just omit it. (see Scope.count() )
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4. Oracle handles foreign keys a bit differently:
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A. REFERENCES is implicit
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B. ON UPDATE is not supported
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(see scope.addForeignKey() )
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5. Searching a blob requires using a function from the dbms_lob package like
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instr() and specifying the offset and number of matches.
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(see oci8.SearchBlob() )
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6 Trailing semicolons are not allowed at the end of Oracle sql statements
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(so they were removed in the unit tests)
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*/
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