support for statistical functions #21

VirtusaPolarisGTO · Jun 5, 2017 · bc3eeed · bc3eeed
1 parent d405b56
commit bc3eeed
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diff --git a/core/src/main/groovy/com/virtusa/gto/nyql/db/QFunctions.groovy b/core/src/main/groovy/com/virtusa/gto/nyql/db/QFunctions.groovy
@@ -582,6 +582,28 @@ trait QFunctions {
         String.format('COUNT(%s)', ___resolveIn(___val(c) ?: '*', ___pm(c)))
     }
 
+    /**
+     * --------------------------------------------------------------
+     * Stat functions
+     * --------------------------------------------------------------
+     */
+
+    @CompileStatic String stat_stddevpop(cx) {
+        String.format('STDDEV_POP(%s)', ___resolveInP(cx))
+    }
+
+    @CompileStatic String stat_stddevsamp(cx) {
+        String.format('STDDEV_SAMP(%s)', ___resolveInP(cx))
+    }
+
+    @CompileStatic String stat_varpop(cx) {
+        String.format('VAR_POP(%s)', ___resolveInP(cx))
+    }
+
+    @CompileStatic String stat_varsamp(cx) {
+        String.format('VAR_SAMP(%s)', ___resolveInP(cx))
+    }
+
     /**
      * Returns the sum value of given column.
      *

diff --git a/core/src/main/groovy/com/virtusa/gto/nyql/traits/FunctionTraits.groovy b/core/src/main/groovy/com/virtusa/gto/nyql/traits/FunctionTraits.groovy
@@ -32,6 +32,12 @@ trait FunctionTraits {
     @CompileStatic FunctionColumn AVG(Object column)      { fColumn(column, 'avg') }
     @CompileStatic FunctionColumn SUM(Object column)      { fColumn(column, 'sum') }
 
+    // stats functions
+    @CompileStatic FunctionColumn STDDEV_POP(Object expr) { fColumn(expr, 'stat_stddevpop') }
+    @CompileStatic FunctionColumn STDDEV_SAMP(Object expr) { fColumn(expr, 'stat_stddevsamp') }
+    @CompileStatic FunctionColumn VAR_POP(Object expr) { fColumn(expr, 'stat_varpop') }
+    @CompileStatic FunctionColumn VAR_SAMP(Object expr) { fColumn(expr, 'stat_varsamp') }
+
     @CompileStatic FunctionColumn LCASE(Object column)    { fColumn(column, 'lcase') }
     @CompileStatic FunctionColumn UCASE(Object column)    { fColumn(column, 'ucase') }
     @CompileStatic FunctionColumn TRIM(Object column)     { fColumn(column, 'trim') }

diff --git a/docs/functions.md b/docs/functions.md
@@ -145,6 +145,17 @@ Album.rating + 1 AS newRating
 |TAN (_value_ )  | Returns the tangent for the given value. |
 |TRUNCATE(_column, d_ ) | Truncate the given decimal number to _d_ decimal places. This does not _round_ the number. Negative _d_ values will truncate before the decimal point. |
 
+
+### Stats Functions
+
+| Function | Details |
+|---|---|
+|STDDEV_POP (_column_ ) | Population standard deviation of values in given column. |
+|STDDEV_SAMP (_column_ ) | Sample standard deviation of values in given column. |
+|VAR_POP (_column_ ) | Population variance of values in given column. |
+|VAR_SAMP (_column_ ) | Sample variance of values in given column. |
+
+
 ### Casting Functions
 
 | Function | Details |

diff --git a/tests/scripts/projection/func2_projection.groovy b/tests/scripts/projection/func2_projection.groovy
@@ -157,4 +157,15 @@
             mssql: "SELECT ROUND(l.v, 2, 1) FROM `Logs` l",
             pg:    "SELECT TRUNC(l.v, 2) FROM `Logs` l"
     ],
+
+    $DSL.select {
+        TARGET (Stats.alias('s'))
+        FETCH (STDDEV_POP(s.income), STDDEV_SAMP(s.income), VAR_POP(s.income), VAR_SAMP(s.income))
+        GROUP_BY (s.year)
+    },
+    [
+            mysql: "SELECT STDDEV_POP(s.income), STDDEV_SAMP(s.income), VAR_POP(s.income), VAR_SAMP(s.income) FROM `Stats` s GROUP BY s.year",
+            mssql: "SELECT STDEVP(s.income), STDEV(s.income), VARP(s.income), VAR(s.income) FROM `Stats` s GROUP BY s.year",
+            pg:    "SELECT STDDEV_POP(s.income), STDDEV_SAMP(s.income), VAR_POP(s.income), VAR_SAMP(s.income) FROM `Stats` s GROUP BY s.year"
+    ],
 ]
diff --git a/translators/mssql/src/main/groovy/com/virtusa/gto/nyql/db/mssql/MSSqlFunctions.groovy b/translators/mssql/src/main/groovy/com/virtusa/gto/nyql/db/mssql/MSSqlFunctions.groovy
@@ -20,6 +20,26 @@ abstract class MSSqlFunctions extends AbstractSQLTranslator implements QFunction
         super(theOptions)
     }
 
+    @Override
+    String stat_stddevpop(Object cx) {
+        return String.format('STDEVP(%s)', ___resolveInP(cx))
+    }
+
+    @Override
+    String stat_stddevsamp(Object cx) {
+        return String.format('STDEV(%s)', ___resolveInP(cx))
+    }
+
+    @Override
+    String stat_varpop(Object cx) {
+        return String.format('VARP(%s)', ___resolveInP(cx))
+    }
+
+    @Override
+    String stat_varsamp(Object cx) {
+        return String.format('VAR(%s)', ___resolveInP(cx))
+    }
+
     @CompileStatic
     @Override
     String truncate(Object cx) {