Merge pull request #1648 from ilm-informatique/arrayFunctions

Add functions ARRAY_CAT(), ARRAY_APPEND() and ARRAY_SLICE()

h2/src/docsrc/help/help.csv

@@ -4842,6 +4842,34 @@ Returns NULL if the specified array is NULL.
 CALL ARRAY_CONTAINS(ARRAY['Hello', 'World'], 'Hello')
 "
 
+"Functions (System)","ARRAY_CAT","
+ARRAY_CAT(arrayExpression, arrayExpression)
+","
+Returns the concatenation of two arrays.
+Returns NULL if any parameter is NULL.
+","
+CALL ARRAY_CAT(ARRAY[1, 2], ARRAY[3, 4])
+"
+
+"Functions (System)","ARRAY_APPEND","
+ARRAY_APPEND(arrayExpression, value)
+","
+Append an element to the end of an array.
+Returns NULL if any parameter is NULL.
+","
+CALL ARRAY_APPEND(ARRAY[1, 2], 3)
+"
+
+"Functions (System)","ARRAY_SLICE","
+ARRAY_SLICE(arrayExpression, lowerBoundInt, upperBoundInt)
+","
+Returns elements from the array as specified by the lower and upper bound parameters.
+Both parameters are inclusive and the first element has index 1, i.e. ARRAY_SLICE(a, 2, 2) has only the second element.
+Returns NULL if any parameter is NULL or if an index is out of bounds.
+","
+CALL ARRAY_SLICE(ARRAY[1, 2, 3, 4], 1, 3)
+"
+
 "Functions (System)","AUTOCOMMIT","
 AUTOCOMMIT()
 ","

h2/src/docsrc/html/changelog.html

@@ -21,6 +21,8 @@ Change Log
 
 <h2>Next Version (unreleased)</h2>
 <ul>
+<li>PR #1648: Add functions ARRAY_CAT(), ARRAY_APPEND() and ARRAY_SLICE()
+</li>
 <li>PR #1638: Add support for Java 11 to test suite
 </li>
 <li>PR #1637: Remove explicit unboxing

h2/src/docsrc/html/features.html

@@ -959,6 +959,7 @@ or the SQL statement <code>SET MODE PostgreSQL</code>.
 </li><li>Fixed-width strings are padded with spaces.
 </li><li>MONEY data type is treated like NUMERIC(19, 2) data type.
 </li><li>Datetime value functions return the same value within a transaction.
+</li><li>ARRAY_SLICE() out of bounds parameters are silently corrected.
 </li></ul>
 
 <h3>Ignite Compatibility Mode</h3>

h2/src/main/org/h2/expression/function/Function.java

@@ -16,6 +16,7 @@ import java.sql.Connection;
 import java.sql.ResultSet;
 import java.sql.SQLException;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.HashMap;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
@@ -27,6 +28,7 @@ import org.h2.command.Parser;
 import org.h2.engine.Constants;
 import org.h2.engine.Database;
 import org.h2.engine.Mode;
+import org.h2.engine.Mode.ModeEnum;
 import org.h2.engine.Session;
 import org.h2.expression.Expression;
 import org.h2.expression.ExpressionColumn;
@@ -61,6 +63,7 @@ import org.h2.util.Utils;
 import org.h2.value.DataType;
 import org.h2.value.ExtTypeInfo;
 import org.h2.value.Value;
+import org.h2.value.ValueArray;
 import org.h2.value.ValueBoolean;
 import org.h2.value.ValueBytes;
 import org.h2.value.ValueCollectionBase;
@@ -135,7 +138,7 @@ public class Function extends Expression implements FunctionCall {
             CANCEL_SESSION = 221, SET = 222, TABLE = 223, TABLE_DISTINCT = 224,
             FILE_READ = 225, TRANSACTION_ID = 226, TRUNCATE_VALUE = 227,
             NVL2 = 228, DECODE = 229, ARRAY_CONTAINS = 230, FILE_WRITE = 232,
-            UNNEST = 233;
+            UNNEST = 233, ARRAY_CONCAT = 234, ARRAY_APPEND = 235, ARRAY_SLICE = 236;
 
     public static final int REGEXP_LIKE = 240;
 
@@ -419,6 +422,9 @@ public class Function extends Expression implements FunctionCall {
         addFunction("ARRAY_GET", ARRAY_GET,
                 2, Value.NULL);
         addFunctionWithNull("ARRAY_CONTAINS", ARRAY_CONTAINS, 2, Value.BOOLEAN);
+        addFunction("ARRAY_CAT", ARRAY_CONCAT, 2, Value.ARRAY);
+        addFunction("ARRAY_APPEND", ARRAY_APPEND, 2, Value.ARRAY);
+        addFunction("ARRAY_SLICE", ARRAY_SLICE, 3, Value.ARRAY);
         addFunction("CSVREAD", CSVREAD,
                 VAR_ARGS, Value.RESULT_SET, false, false, false, true);
         addFunction("CSVWRITE", CSVWRITE,
@@ -1542,6 +1548,61 @@ public class Function extends Expression implements FunctionCall {
             }
             break;
         }
+        case ARRAY_CONCAT: {
+            final ValueArray array = (ValueArray) v0.convertTo(Value.ARRAY);
+            final ValueArray array2 = (ValueArray) v1.convertTo(Value.ARRAY);
+            if (!array.getComponentType().equals(array2.getComponentType()))
+                throw DbException.get(ErrorCode.GENERAL_ERROR_1, "Expected component type " + array.getComponentType()
+                        + " but got " + array2.getComponentType());
+            final Value[] res = Arrays.copyOf(array.getList(), array.getList().length + array2.getList().length);
+            System.arraycopy(array2.getList(), 0, res, array.getList().length, array2.getList().length);
+            result = ValueArray.get(array.getComponentType(), res);
+            break;
+        }
+        case ARRAY_APPEND: {
+            final ValueArray array = (ValueArray) v0.convertTo(Value.ARRAY);
+            if (v1 != ValueNull.INSTANCE && array.getComponentType() != Object.class
+                    && !array.getComponentType().isInstance(v1.getObject()))
+                throw DbException.get(ErrorCode.GENERAL_ERROR_1,
+                        "Expected component type " + array.getComponentType() + " but got " + v1.getClass());
+            final Value[] res = Arrays.copyOf(array.getList(), array.getList().length + 1);
+            res[array.getList().length] = v1;
+            result = ValueArray.get(array.getComponentType(), res);
+            break;
+        }
+        case ARRAY_SLICE: {
+            result = null;
+            final ValueArray array = (ValueArray) v0.convertTo(Value.ARRAY);
+            // SQL is 1-based
+            int index1 = v1.getInt() - 1;
+            // 1-based and inclusive as postgreSQL (-1+1)
+            int index2 = v2.getInt();
+            // https://www.postgresql.org/docs/current/arrays.html#ARRAYS-ACCESSING
+            // For historical reasons postgreSQL ignore invalid indexes
+            final boolean isPG = database.getMode().getEnum() == ModeEnum.PostgreSQL;
+            if (index1 > index2) {
+                if (isPG)
+                    result = ValueArray.get(array.getComponentType(), new Value[0]);
+                else
+                    result = ValueNull.INSTANCE;
+            } else {
+                if (index1 < 0) {
+                    if (isPG)
+                        index1 = 0;
+                    else
+                        result = ValueNull.INSTANCE;
+                }
+                if (index2 > array.getList().length) {
+                    if (isPG)
+                        index2 = array.getList().length;
+                    else
+                        result = ValueNull.INSTANCE;
+                }
+            }
+            if (result == null)
+                result = ValueArray.get(array.getComponentType(), Arrays.copyOfRange(array.getList(), index1, index2));
+            break;
+        }
         case LINK_SCHEMA: {
             session.getUser().checkAdmin();
             Connection conn = session.createConnection(false);

h2/src/test/org/h2/test/scripts/TestScript.java

@@ -186,8 +186,8 @@ public class TestScript extends TestDb {
                 "xmlnode", "xmlstartdoc", "xmltext" }) {
             testScript("functions/string/" + s + ".sql");
         }
-        for (String s : new String[] { "array-contains", "array-get",
-                "array-length", "autocommit", "cancel-session", "casewhen",
+        for (String s : new String[] { "array-cat", "array-contains", "array-get",
+                "array-length","array-slice", "autocommit", "cancel-session", "casewhen",
                 "cast", "coalesce", "convert", "csvread", "csvwrite", "currval",
                 "database-path", "database", "decode", "disk-space-used",
                 "file-read", "file-write", "greatest", "h2version", "identity",

h2/src/test/org/h2/test/scripts/functions/system/array-cat.sql

+-- Copyright 2004-2019 H2 Group. Multiple-Licensed under the MPL 2.0,
+-- and the EPL 1.0 (http://h2database.com/html/license.html).
+-- Initial Developer: H2 Group
+--
+
+select array_cat(ARRAY[1, 2], ARRAY[3, 4]) = ARRAY[1, 2, 3, 4];
+>> TRUE
+
+select array_cat(ARRAY[1, 2], null) is null;
+>> TRUE
+
+select array_cat(null, ARRAY[1, 2]) is null;
+>> TRUE
+
+select array_append(ARRAY[1, 2], 3) = ARRAY[1, 2, 3];
+>> TRUE
+
+select array_append(ARRAY[1, 2], null) is null;
+>> TRUE
+
+select array_append(null, 3) is null;
+>> TRUE

h2/src/test/org/h2/test/scripts/functions/system/array-slice.sql

+-- Copyright 2004-2019 H2 Group. Multiple-Licensed under the MPL 2.0,
+-- and the EPL 1.0 (http://h2database.com/html/license.html).
+-- Initial Developer: H2 Group
+--
+
+select array_slice(ARRAY[1, 2, 3, 4], 1, 1) = ARRAY[1];
+>> TRUE
+
+select array_slice(ARRAY[1, 2, 3, 4], 1, 3) = ARRAY[1, 2, 3];
+>> TRUE
+
+-- test invalid indexes
+select array_slice(ARRAY[1, 2, 3, 4], 3, 1) is null;
+>> TRUE
+
+select array_slice(ARRAY[1, 2, 3, 4], 0, 3) is null;
+>> TRUE
+
+select array_slice(ARRAY[1, 2, 3, 4], 1, 5) is null;
+>> TRUE
+
+-- in PostgreSQL, indexes are corrected
+SET MODE PostgreSQL;
+> ok
+
+select array_slice(ARRAY[1, 2, 3, 4], 3, 1) = ARRAY[];
+>> TRUE
+
+select array_slice(ARRAY[1, 2, 3, 4], 0, 3) = ARRAY[1, 2, 3];
+>> TRUE
+
+select array_slice(ARRAY[1, 2, 3, 4], 1, 5) = ARRAY[1, 2, 3, 4];
+>> TRUE
+
+SET MODE Regular;
+> ok
+
+-- null parameters
+select array_slice(null, 1, 3) is null;
+>> TRUE
+
+select array_slice(ARRAY[1, 2, 3, 4], null, 3) is null;
+>> TRUE
+
+select array_slice(ARRAY[1, 2, 3, 4], 1, null) is null;
+>> TRUE