MySQL JOINs: Row Generation Without Oracle's CONNECT BY
Unlike Oracle's convenient CONNECT BY LEVEL
clause for generating row sets in joins, MySQL lacks a direct equivalent. Oracle's approach simplifies creating sequences for joins:
<code class="language-sql">SELECT * FROM dual CONNECT BY LEVEL < p></code>
Similarly, MS SQL Server uses recursion:
<code class="language-sql">WITH hier(row) AS ( SELECT 1 UNION ALL SELECT row + 1 FROM hier WHERE row < p></code>
PostgreSQL offers generate_series
:
<code class="language-sql">SELECT * FROM generate_series(1, n)</code>
However, MySQL requires alternative strategies for generating rows needed in JOIN operations. These often involve workarounds or external tools due to the absence of a built-in row generator.
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