yujunjun/knex
1
0
Fork 0
mirror of https://github.com/knex/knex.git synced 2025-08-03 22:31:58 +00:00
Code Issues Packages Projects Releases Wiki Activity
knex/docs/clients/base/sqlite3/grammar.html
Tim Griesser 6bd3bca2f9 documentation rebuild
2013-09-18 11:57:47 -04:00

60 lines
15 KiB
HTML
Raw Blame History

<!DOCTYPE html><html lang="en"><head><title>clients/base/sqlite3/grammar</title></head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0, minimum-scale=1.0, maximum-scale=1.0"><meta name="groc-relative-root" content="../../../"><meta name="groc-document-path" content="clients/base/sqlite3/grammar"><meta name="groc-project-path" content="clients/base/sqlite3/grammar.js"><link rel="stylesheet" type="text/css" media="all" href="../../../assets/style.css"><script type="text/javascript" src="../../../assets/behavior.js"></script><body><div id="meta"><div class="file-path">clients/base/sqlite3/grammar.js</div></div><div id="document"><div class="segment"><div class="comments"><div class="wrapper"><h2 id="sqlite3-grammar">SQLite3 Grammar</h2></div></div></div><div class="segment"><div class="code"><div class="wrapper"><span class="p">(</span><span class="kd">function</span><span class="p">(</span><span class="nx">define</span><span class="p">)</span> <span class="p">{</span>
<span class="s2">&quot;use strict&quot;</span><span class="p">;</span></div></div></div><div class="segment"><div class="comments"><div class="wrapper"><p>The SQLite3 base is a bit different than the other clients,
in that it may be run on both the client and server. So add another
layer to the prototype chain.</p></div></div><div class="code"><div class="wrapper"><span class="nx">define</span><span class="p">(</span><span class="kd">function</span><span class="p">(</span><span class="nx">require</span><span class="p">,</span> <span class="nx">exports</span><span class="p">)</span> <span class="p">{</span>
<span class="kd">var</span> <span class="nx">_</span> <span class="o">=</span> <span class="nx">require</span><span class="p">(</span><span class="s1">&#39;underscore&#39;</span><span class="p">);</span>
<span class="kd">var</span> <span class="nx">Helpers</span> <span class="o">=</span> <span class="nx">require</span><span class="p">(</span><span class="s1">&#39;../../../lib/helpers&#39;</span><span class="p">).</span><span class="nx">Helpers</span><span class="p">;</span>
<span class="kd">var</span> <span class="nx">baseGrammar</span> <span class="o">=</span> <span class="nx">require</span><span class="p">(</span><span class="s1">&#39;../grammar&#39;</span><span class="p">).</span><span class="nx">baseGrammar</span><span class="p">;</span></div></div></div><div class="segment"><div class="comments"><div class="wrapper"><p>Extends the standard sql grammar, with any SQLite specific
dialect oddities.</p></div></div><div class="code"><div class="wrapper"> <span class="nx">exports</span><span class="p">.</span><span class="nx">grammar</span> <span class="o">=</span> <span class="nx">_</span><span class="p">.</span><span class="nx">defaults</span><span class="p">({</span></div></div></div><div class="segment"><div class="comments"><div class="wrapper"><p>The keyword identifier wrapper format.</p></div></div><div class="code"><div class="wrapper"> <span class="nx">wrapValue</span><span class="o">:</span> <span class="kd">function</span><span class="p">(</span><span class="nx">value</span><span class="p">)</span> <span class="p">{</span>
<span class="k">return</span> <span class="p">(</span><span class="nx">value</span> <span class="o">!==</span> <span class="s1">&#39;*&#39;</span> <span class="o">?</span> <span class="nx">Helpers</span><span class="p">.</span><span class="nx">format</span><span class="p">(</span><span class="s1">&#39;&quot;%s&quot;&#39;</span><span class="p">,</span> <span class="nx">value</span><span class="p">)</span> <span class="o">:</span> <span class="s2">&quot;*&quot;</span><span class="p">);</span>
<span class="p">},</span></div></div></div><div class="segment"><div class="comments"><div class="wrapper"><p>Compile the "order by" portions of the query.</p></div></div><div class="code"><div class="wrapper"> <span class="nx">compileOrders</span><span class="o">:</span> <span class="kd">function</span><span class="p">(</span><span class="nx">qb</span><span class="p">,</span> <span class="nx">orders</span><span class="p">)</span> <span class="p">{</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">orders</span><span class="p">.</span><span class="nx">length</span> <span class="o">===</span> <span class="mi">0</span><span class="p">)</span> <span class="k">return</span><span class="p">;</span>
<span class="k">return</span> <span class="s2">&quot;order by &quot;</span> <span class="o">+</span> <span class="nx">orders</span><span class="p">.</span><span class="nx">map</span><span class="p">(</span><span class="kd">function</span><span class="p">(</span><span class="nx">order</span><span class="p">)</span> <span class="p">{</span>
<span class="k">return</span> <span class="k">this</span><span class="p">.</span><span class="nx">wrap</span><span class="p">(</span><span class="nx">order</span><span class="p">.</span><span class="nx">column</span><span class="p">)</span> <span class="o">+</span> <span class="s2">&quot; collate nocase &quot;</span> <span class="o">+</span> <span class="nx">order</span><span class="p">.</span><span class="nx">direction</span><span class="p">;</span>
<span class="p">},</span> <span class="k">this</span><span class="p">).</span><span class="nx">join</span><span class="p">(</span><span class="s1">&#39;, &#39;</span><span class="p">);</span>
<span class="p">},</span></div></div></div><div class="segment"><div class="comments"><div class="wrapper"><p>Compile an insert statement into SQL.</p></div></div><div class="code"><div class="wrapper"> <span class="nx">compileInsert</span><span class="o">:</span> <span class="kd">function</span><span class="p">(</span><span class="nx">qb</span><span class="p">)</span> <span class="p">{</span>
<span class="kd">var</span> <span class="nx">values</span> <span class="o">=</span> <span class="nx">qb</span><span class="p">.</span><span class="nx">values</span><span class="p">;</span>
<span class="kd">var</span> <span class="nx">table</span> <span class="o">=</span> <span class="k">this</span><span class="p">.</span><span class="nx">wrapTable</span><span class="p">(</span><span class="nx">qb</span><span class="p">.</span><span class="nx">table</span><span class="p">);</span>
<span class="kd">var</span> <span class="nx">columns</span> <span class="o">=</span> <span class="nx">_</span><span class="p">.</span><span class="nx">pluck</span><span class="p">(</span><span class="nx">values</span><span class="p">[</span><span class="mi">0</span><span class="p">],</span> <span class="mi">0</span><span class="p">);</span></div></div></div><div class="segment"><div class="comments"><div class="wrapper"><p>If there are any "where" clauses, we need to omit
any bindings that may have been associated with them.</p></div></div><div class="code"><div class="wrapper"> <span class="k">if</span> <span class="p">(</span><span class="nx">qb</span><span class="p">.</span><span class="nx">wheres</span><span class="p">.</span><span class="nx">length</span> <span class="o">&gt;</span> <span class="mi">0</span><span class="p">)</span> <span class="k">this</span><span class="p">.</span><span class="nx">clearWhereBindings</span><span class="p">(</span><span class="nx">qb</span><span class="p">);</span></div></div></div><div class="segment"><div class="comments"><div class="wrapper"><p>If there is only one record being inserted, we will just use the usual query
grammar insert builder because no special syntax is needed for the single
row inserts in SQLite. However, if there are multiples, we'll continue.</p></div></div><div class="code"><div class="wrapper"> <span class="k">if</span> <span class="p">(</span><span class="nx">values</span><span class="p">.</span><span class="nx">length</span> <span class="o">===</span> <span class="mi">1</span><span class="p">)</span> <span class="p">{</span>
<span class="kd">var</span> <span class="nx">sql</span> <span class="o">=</span> <span class="s1">&#39;insert into &#39;</span> <span class="o">+</span> <span class="nx">table</span> <span class="o">+</span> <span class="s1">&#39; &#39;</span><span class="p">;</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">columns</span><span class="p">.</span><span class="nx">length</span> <span class="o">===</span> <span class="mi">0</span><span class="p">)</span> <span class="p">{</span>
<span class="nx">sql</span> <span class="o">+=</span> <span class="s1">&#39;default values&#39;</span><span class="p">;</span>
<span class="p">}</span> <span class="k">else</span> <span class="p">{</span>
<span class="nx">sql</span> <span class="o">+=</span> <span class="s2">&quot;(&quot;</span> <span class="o">+</span> <span class="k">this</span><span class="p">.</span><span class="nx">columnize</span><span class="p">(</span><span class="nx">columns</span><span class="p">)</span> <span class="o">+</span> <span class="s2">&quot;) values &quot;</span> <span class="o">+</span> <span class="s2">&quot;(&quot;</span> <span class="o">+</span> <span class="k">this</span><span class="p">.</span><span class="nx">parameterize</span><span class="p">(</span><span class="nx">_</span><span class="p">.</span><span class="nx">pluck</span><span class="p">(</span><span class="nx">values</span><span class="p">[</span><span class="mi">0</span><span class="p">],</span> <span class="mi">1</span><span class="p">))</span> <span class="o">+</span> <span class="s2">&quot;)&quot;</span><span class="p">;</span>
<span class="p">}</span>
<span class="k">return</span> <span class="nx">sql</span><span class="p">;</span>
<span class="p">}</span>
<span class="kd">var</span> <span class="nx">blocks</span> <span class="o">=</span> <span class="p">[];</span></div></div></div><div class="segment"><div class="comments"><div class="wrapper"><p>SQLite requires us to build the multi-row insert as a listing of select with
unions joining them together. So we'll build out this list of columns and
then join them all together with select unions to complete the queries.</p></div></div><div class="code"><div class="wrapper"> <span class="k">for</span> <span class="p">(</span><span class="kd">var</span> <span class="nx">i</span> <span class="o">=</span> <span class="mi">0</span><span class="p">,</span> <span class="nx">l</span> <span class="o">=</span> <span class="nx">columns</span><span class="p">.</span><span class="nx">length</span><span class="p">;</span> <span class="nx">i</span> <span class="o">&lt;</span> <span class="nx">l</span><span class="p">;</span> <span class="nx">i</span><span class="o">++</span><span class="p">)</span> <span class="p">{</span>
<span class="nx">blocks</span><span class="p">.</span><span class="nx">push</span><span class="p">(</span><span class="s1">&#39;? as &#39;</span> <span class="o">+</span> <span class="k">this</span><span class="p">.</span><span class="nx">wrap</span><span class="p">(</span><span class="nx">columns</span><span class="p">[</span><span class="nx">i</span><span class="p">]));</span>
<span class="p">}</span>
<span class="kd">var</span> <span class="nx">joinedColumns</span> <span class="o">=</span> <span class="nx">blocks</span><span class="p">.</span><span class="nx">join</span><span class="p">(</span><span class="s1">&#39;, &#39;</span><span class="p">);</span>
<span class="nx">blocks</span> <span class="o">=</span> <span class="p">[];</span>
<span class="k">for</span> <span class="p">(</span><span class="nx">i</span> <span class="o">=</span> <span class="mi">0</span><span class="p">,</span> <span class="nx">l</span> <span class="o">=</span> <span class="nx">values</span><span class="p">.</span><span class="nx">length</span><span class="p">;</span> <span class="nx">i</span> <span class="o">&lt;</span> <span class="nx">l</span><span class="p">;</span> <span class="nx">i</span><span class="o">++</span><span class="p">)</span> <span class="p">{</span>
<span class="nx">blocks</span><span class="p">.</span><span class="nx">push</span><span class="p">(</span><span class="nx">joinedColumns</span><span class="p">);</span>
<span class="p">}</span>
<span class="k">return</span> <span class="s2">&quot;insert into &quot;</span> <span class="o">+</span> <span class="nx">table</span> <span class="o">+</span> <span class="s2">&quot; (&quot;</span> <span class="o">+</span> <span class="k">this</span><span class="p">.</span><span class="nx">columnize</span><span class="p">(</span><span class="nx">columns</span><span class="p">)</span> <span class="o">+</span> <span class="s2">&quot;) select &quot;</span> <span class="o">+</span> <span class="nx">blocks</span><span class="p">.</span><span class="nx">join</span><span class="p">(</span><span class="s1">&#39; union all select &#39;</span><span class="p">);</span>
<span class="p">},</span></div></div></div><div class="segment"><div class="comments"><div class="wrapper"><p>Compile a truncate table statement into SQL.</p></div></div><div class="code"><div class="wrapper"> <span class="nx">compileTruncate</span><span class="o">:</span> <span class="kd">function</span> <span class="p">(</span><span class="nx">qb</span><span class="p">)</span> <span class="p">{</span>
<span class="kd">var</span> <span class="nx">sql</span> <span class="o">=</span> <span class="p">[];</span>
<span class="kd">var</span> <span class="nx">table</span> <span class="o">=</span> <span class="k">this</span><span class="p">.</span><span class="nx">wrapTable</span><span class="p">(</span><span class="nx">qb</span><span class="p">.</span><span class="nx">table</span><span class="p">);</span>
<span class="nx">sql</span><span class="p">.</span><span class="nx">push</span><span class="p">(</span><span class="s1">&#39;delete from sqlite_sequence where name = &#39;</span> <span class="o">+</span> <span class="nx">table</span><span class="p">);</span>
<span class="nx">sql</span><span class="p">.</span><span class="nx">push</span><span class="p">(</span><span class="s1">&#39;delete from &#39;</span> <span class="o">+</span> <span class="nx">table</span><span class="p">);</span>
<span class="k">return</span> <span class="nx">sql</span><span class="p">;</span>
<span class="p">}</span>
<span class="p">},</span> <span class="nx">baseGrammar</span><span class="p">);</span>
<span class="p">});</span>
<span class="p">})(</span>
<span class="k">typeof</span> <span class="nx">define</span> <span class="o">===</span> <span class="s1">&#39;function&#39;</span> <span class="o">&amp;&amp;</span> <span class="nx">define</span><span class="p">.</span><span class="nx">amd</span> <span class="o">?</span> <span class="nx">define</span> <span class="o">:</span> <span class="kd">function</span> <span class="p">(</span><span class="nx">factory</span><span class="p">)</span> <span class="p">{</span> <span class="nx">factory</span><span class="p">(</span><span class="nx">require</span><span class="p">,</span> <span class="nx">exports</span><span class="p">,</span> <span class="nx">module</span><span class="p">);</span> <span class="p">}</span>
<span class="p">);</span></div></div></div></div></body></html>
Reference in New Issue View Git Blame Copy Permalink