[feat] Support for the legacy Postgres named parameter

src/main/java/net/sf/jsqlparser/expression/ExpressionVisitor.java

@@ -781,4 +781,10 @@ default void visit(Inverse inverse) {
     <S> T visit(FromQuery fromQuery, S context);
 
     <S> T visit(DateUnitExpression dateUnitExpression, S context);
+
+    <S> T visit(PostgresNamedFunctionParameter postgresNamedFunctionParameter, S context);
+
+    default void visit(PostgresNamedFunctionParameter postgresNamedFunctionParameter) {
+        this.visit(postgresNamedFunctionParameter, null);
+    }
 }

src/main/java/net/sf/jsqlparser/expression/ExpressionVisitorAdapter.java

@@ -743,6 +743,11 @@ public <S> T visit(OracleNamedFunctionParameter oracleNamedFunctionParameter, S
         return oracleNamedFunctionParameter.getExpression().accept(this, context);
     }
 
+    @Override
+    public <S> T visit(PostgresNamedFunctionParameter postgresNamedFunctionParameter, S context) {
+        return postgresNamedFunctionParameter.getExpression().accept(this, context);
+    }
+
     @Override
     public <S> T visit(GeometryDistance geometryDistance, S context) {
         return visitBinaryExpression(geometryDistance, context);

src/main/java/net/sf/jsqlparser/expression/PostgresNamedFunctionParameter.java

@@ -0,0 +1,55 @@
+/*-
+ * #%L
+ * JSQLParser library
+ * %%
+ * Copyright (C) 2004 - 2021 JSQLParser
+ * %%
+ * Dual licensed under GNU LGPL 2.1 or Apache License 2.0
+ * #L%
+ */
+package net.sf.jsqlparser.expression;
+
+import net.sf.jsqlparser.parser.ASTNodeAccessImpl;
+
+import java.util.Objects;
+
+/**
+ * @author <a href="mailto:andreas@manticore-projects.com">Andreas Reichel</a>
+ */
+public class PostgresNamedFunctionParameter extends ASTNodeAccessImpl implements Expression {
+    private final String name;
+    private final Expression expression;
+
+    public PostgresNamedFunctionParameter(String name, Expression expression) {
+        this.name = Objects.requireNonNull(name,
+                "The NAME of the PostgresNamedFunctionParameter must not be null.");
+        this.expression = Objects.requireNonNull(expression,
+                "The EXPRESSION of the PostgresNamedFunctionParameter must not be null.");
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public Expression getExpression() {
+        return expression;
+    }
+
+    @Override
+    public <T, S> T accept(ExpressionVisitor<T> expressionVisitor, S context) {
+        return expressionVisitor.visit(this, context);
+    }
+
+    public StringBuilder appendTo(StringBuilder builder) {
+        builder.append(name)
+                .append(" := ")
+                .append(expression);
+
+        return builder;
+    }
+
+    @Override
+    public String toString() {
+        return appendTo(new StringBuilder()).toString();
+    }
+}

src/main/java/net/sf/jsqlparser/util/TablesNamesFinder.java

@@ -1758,6 +1758,12 @@ public <S> Void visit(OracleNamedFunctionParameter oracleNamedFunctionParameter,
         return null;
     }
 
+    @Override
+    public <S> Void visit(PostgresNamedFunctionParameter postgresNamedFunctionParameter, S context) {
+        postgresNamedFunctionParameter.getExpression().accept(this, context);
+        return null;
+    }
+
     @Override
     public <S> Void visit(RenameTableStatement renameTableStatement, S context) {
         for (Map.Entry<Table, Table> e : renameTableStatement.getTableNames()) {

src/main/java/net/sf/jsqlparser/util/deparser/ExpressionDeParser.java

@@ -52,6 +52,7 @@
 import net.sf.jsqlparser.expression.OracleHint;
 import net.sf.jsqlparser.expression.OracleNamedFunctionParameter;
 import net.sf.jsqlparser.expression.OverlapsCondition;
+import net.sf.jsqlparser.expression.PostgresNamedFunctionParameter;
 import net.sf.jsqlparser.expression.RangeExpression;
 import net.sf.jsqlparser.expression.RowConstructor;
 import net.sf.jsqlparser.expression.RowGetExpression;
@@ -1835,4 +1836,13 @@ public <S> StringBuilder visit(FromQuery fromQuery, S context) {
     public <S> StringBuilder visit(DateUnitExpression dateUnitExpression, S context) {
         return builder.append(dateUnitExpression.toString());
     }
+
+    @Override
+    public <S> StringBuilder visit(PostgresNamedFunctionParameter postgresNamedFunctionParameter,
+                                   S context) {
+        builder.append(postgresNamedFunctionParameter.getName()).append(" := ");
+
+        postgresNamedFunctionParameter.getExpression().accept(this, context);
+        return builder;
+    }
 }

src/main/java/net/sf/jsqlparser/util/validation/validator/ExpressionValidator.java

@@ -51,6 +51,7 @@
 import net.sf.jsqlparser.expression.OracleHint;
 import net.sf.jsqlparser.expression.OracleNamedFunctionParameter;
 import net.sf.jsqlparser.expression.OverlapsCondition;
+import net.sf.jsqlparser.expression.PostgresNamedFunctionParameter;
 import net.sf.jsqlparser.expression.RangeExpression;
 import net.sf.jsqlparser.expression.RowConstructor;
 import net.sf.jsqlparser.expression.RowGetExpression;
@@ -1052,6 +1053,12 @@ public <S> Void visit(OracleNamedFunctionParameter oracleNamedFunctionParameter,
         return null;
     }
 
+    @Override
+    public <S> Void visit(PostgresNamedFunctionParameter postgresNamedFunctionParameter, S context) {
+        postgresNamedFunctionParameter.getExpression().accept(this, context);
+        return null;
+    }
+
     @Override
     public <S> Void visit(AllColumns allColumns, S context) {
         return null;

src/main/jjtree/net/sf/jsqlparser/parser/JSqlParserCC.jjt

@@ -515,6 +515,7 @@ TOKEN: /* SQL Keywords. prefixed with K_ to avoid name clashes */
 |   <K_OR:"OR">
 |   <K_ORA: "ORA">
 |   <K_ORACLE_NAMED_PARAMETER_ASSIGNMENT: "=>">
+|   <K_POSTGRES_NAMED_PARAMETER_ASSIGNMENT: ":=">
 |   <K_ORDER:"ORDER">
 |   <K_ORDINALITY:"ORDINALITY">
 |   <K_OUTER:"OUTER">
@@ -6224,6 +6225,8 @@ ExpressionList ComplexExpressionList():
     (
         LOOKAHEAD(2) expr=OracleNamedFunctionParameter()
         |
+        LOOKAHEAD(2) expr=PostgresNamedFunctionParameter()
+        |
         expr=Expression()
     )
     {
@@ -6235,6 +6238,8 @@ ExpressionList ComplexExpressionList():
         (
             LOOKAHEAD(2) expr=OracleNamedFunctionParameter()
             |
+            LOOKAHEAD(2) expr=PostgresNamedFunctionParameter()
+            |
             LOOKAHEAD(7) expr=LambdaExpression()
             |
             expr=Expression()
@@ -6786,6 +6791,20 @@ OracleNamedFunctionParameter OracleNamedFunctionParameter() : {
     }
 }
 
+PostgresNamedFunctionParameter PostgresNamedFunctionParameter() : {
+    Token token = null;
+    String name = null;
+    Expression expression;
+}
+{
+    ( name=RelObjectNameExt2() | token=<K_OUTER> )
+    <K_POSTGRES_NAMED_PARAMETER_ASSIGNMENT>
+    expression=Expression()
+    {
+        return new PostgresNamedFunctionParameter(name != null ? name : token.image, expression);
+    }
+}
+
 UserVariable UserVariable() : {
     Token tk;
     String varName;

src/test/java/net/sf/jsqlparser/expression/PostgresNamedFunctionParameterTest.java

@@ -0,0 +1,96 @@
+/*-
+ * #%L
+ * JSQLParser library
+ * %%
+ * Copyright (C) 2004 - 2021 JSQLParser
+ * %%
+ * Dual licensed under GNU LGPL 2.1 or Apache License 2.0
+ * #L%
+ */
+package net.sf.jsqlparser.expression;
+
+import net.sf.jsqlparser.JSQLParserException;
+import net.sf.jsqlparser.parser.CCJSqlParserUtil;
+import net.sf.jsqlparser.statement.Statement;
+import net.sf.jsqlparser.statement.StatementVisitorAdapter;
+import net.sf.jsqlparser.test.TestUtils;
+import net.sf.jsqlparser.util.TablesNamesFinder;
+import net.sf.jsqlparser.util.validation.ValidationTestAsserts;
+import net.sf.jsqlparser.util.validation.feature.DatabaseType;
+import net.sf.jsqlparser.util.validation.validator.ExpressionValidator;
+import org.junit.jupiter.api.Test;
+
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+/**
+ *
+ * @author <a href="mailto:andreas@manticore-projects.com">Andreas Reichel</a>
+ */
+public class PostgresNamedFunctionParameterTest {
+
+    /**
+     * This test will parse and deparse the statement and assures the functional coverage by
+     * JSQLParser.
+     *
+     * @throws JSQLParserException
+     */
+    @Test
+    public void testExpression() throws JSQLParserException {
+        String sqlStr =
+                "SELECT concat_lower_or_upper(a := 'Hello', uppercase := true, b := 'World')";
+
+        TestUtils.assertSqlCanBeParsedAndDeparsed(sqlStr, true);
+    }
+
+    /**
+     * This test will trigger the method {@link ExpressionVisitorAdaptor#visit() Visit Method} in
+     * the ExpressionVisitorAdaptor needed for the Code Coverage.
+     *
+     * @throws JSQLParserException
+     */
+    @Test
+    public void testExpressionVisitorAdaptor() throws JSQLParserException {
+        String sqlStr =
+                "SELECT concat_lower_or_upper(a := 'Hello', uppercase := true, b := 'World')";
+
+        CCJSqlParserUtil.parse(sqlStr).accept(new StatementVisitorAdapter());
+
+        // alternatively, for the Expression only
+        CCJSqlParserUtil.parseExpression("a := 'Hello'").accept(new ExpressionVisitorAdapter(),
+                null);
+    }
+
+    /**
+     * This test will trigger the method {@link TableNamesFinder#visit() Visit Method} in the
+     * TableNamesFinder needed for the Code Coverage.
+     *
+     * @throws JSQLParserException
+     */
+    @Test
+    public void testTableNamesFinder() throws JSQLParserException {
+        String sqlStr =
+                "SELECT concat_lower_or_upper(a := 'Hello', uppercase := true, b := 'World') FROM test_table";
+
+        Statement statement = CCJSqlParserUtil.parse(sqlStr);
+        List<String> tables = new TablesNamesFinder<>().getTableList(statement);
+        assertEquals(1, tables.size());
+        assertTrue(tables.contains("test_table"));
+    }
+
+    /**
+     * This test will trigger the method {@link ExpressionValidator#visit() Visit Method} in the
+     * ExpressionValidator needed for the Code Coverage.
+     *
+     * @throws JSQLParserException
+     */
+    @Test
+    public void testValidator() throws JSQLParserException {
+        String sqlStr =
+                "SELECT concat_lower_or_upper(a := 'Hello', uppercase := true, b := 'World') FROM test_table";
+
+        ValidationTestAsserts.validateNoErrors(sqlStr, 1, DatabaseType.POSTGRESQL);
+    }
+}