Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
187 views
in Technique[技术] by (71.8m points)

java - In JDBC, why do parameter indexes for prepared statements begin at 1 instead of 0?

Everywhere else in Java, anything with an index starts at 0. Is there a reason for the change here or is this just bad design?

question from:https://stackoverflow.com/questions/616135/in-jdbc-why-do-parameter-indexes-for-prepared-statements-begin-at-1-instead-of

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Reply

0 votes
by (71.8m points)

Historically, databases have used 1-based indexing for bound parameters. This probably reflects the origins of relational databases in set theory and mathematics, which index elements starting with one, and use zero to represent a null or empty set.

In shell scripts and regular expressions, the zero index usually means something "special". For example, in the case of shell scripts, the zeroth "argument" is actually the command that was invoked.

The choice for JDBC was deliberate but, ultimately, probably causes more confusion and difficulty than it solves.


与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
OGeek|极客中国-欢迎来到极客的世界,一个免费开放的程序员编程交流平台!开放,进步,分享!让技术改变生活,让极客改变未来! Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...