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fix: support ClickHouse C-style ternary operator (? :) in expressions (#2436) (#2466)
Parse cond ? then : else as a TernaryExpression at the boolean-operator level in prattExpressionRest, keeping C-style precedence (binds looser than AND/OR) and right-associativity. A pending ? is disambiguated between this ternary and the PostgreSQL JSON operator via isTernaryAhead, and inside a then-branch a top-level : closes the ternary instead of starting a JSON path, so both dialects keep working. Signed-off-by: 付典 <fudianchn@gmail.com>
1 parent 2989cb1 commit 60b0875

8 files changed

Lines changed: 332 additions & 3 deletions

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

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@@ -737,6 +737,12 @@ default void visit(RangeExpression rangeExpression) {
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this.visit(rangeExpression, null);
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}
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<S> T visit(TernaryExpression ternaryExpression, S context);
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default void visit(TernaryExpression ternaryExpression) {
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this.visit(ternaryExpression, null);
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}
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<S> T visit(TSQLLeftJoin tsqlLeftJoin, S context);
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default void visit(TSQLLeftJoin tsqlLeftJoin) {

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

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@@ -822,6 +822,12 @@ public <S> T visit(RangeExpression rangeExpression, S context) {
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rangeExpression.getEndExpression());
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}
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@Override
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public <S> T visit(TernaryExpression ternaryExpression, S context) {
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return visitExpressions(ternaryExpression, context, ternaryExpression.getCondition(),
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ternaryExpression.getThenExpression(), ternaryExpression.getElseExpression());
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}
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@Override
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public <S> T visit(TSQLLeftJoin tsqlLeftJoin, S context) {
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return visitBinaryExpression(tsqlLeftJoin, context);

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

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@@ -0,0 +1,68 @@
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/*-
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* #%L
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* JSQLParser library
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* %%
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* Copyright (C) 2004 - 2025 JSQLParser
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* %%
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* Dual licensed under GNU LGPL 2.1 or Apache License 2.0
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* #L%
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*/
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package net.sf.jsqlparser.expression;
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import net.sf.jsqlparser.parser.ASTNodeAccessImpl;
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/**
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* The C-style ternary conditional operator {@code condition ? thenExpression : elseExpression},
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* supported for instance by ClickHouse as an alias for {@code if(condition, then, else)}.
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*/
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public class TernaryExpression extends ASTNodeAccessImpl implements Expression {
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private Expression condition;
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private Expression thenExpression;
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private Expression elseExpression;
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public TernaryExpression() {}
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public TernaryExpression(Expression condition, Expression thenExpression,
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Expression elseExpression) {
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this.condition = condition;
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this.thenExpression = thenExpression;
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this.elseExpression = elseExpression;
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}
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public Expression getCondition() {
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return condition;
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}
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public TernaryExpression setCondition(Expression condition) {
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this.condition = condition;
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return this;
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}
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public Expression getThenExpression() {
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return thenExpression;
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}
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public TernaryExpression setThenExpression(Expression thenExpression) {
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this.thenExpression = thenExpression;
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return this;
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}
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public Expression getElseExpression() {
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return elseExpression;
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}
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public TernaryExpression setElseExpression(Expression elseExpression) {
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this.elseExpression = elseExpression;
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return this;
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}
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@Override
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public String toString() {
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return condition + " ? " + thenExpression + " : " + elseExpression;
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}
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@Override
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public <T, S> T accept(ExpressionVisitor<T> expressionVisitor, S context) {
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return expressionVisitor.visit(this, context);
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}
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}

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

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Original file line numberDiff line numberDiff line change
@@ -249,6 +249,14 @@ public <S> Void visit(RangeExpression rangeExpression, S context) {
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return null;
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}
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@Override
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public <S> Void visit(TernaryExpression ternaryExpression, S context) {
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ternaryExpression.getCondition().accept(this, context);
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ternaryExpression.getThenExpression().accept(this, context);
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ternaryExpression.getElseExpression().accept(this, context);
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return null;
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}
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/**
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* Main entry for this Tool class. A list of found tables is returned.
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*/

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

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@@ -62,6 +62,7 @@
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import net.sf.jsqlparser.expression.OverlapsCondition;
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import net.sf.jsqlparser.expression.PostgresNamedFunctionParameter;
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import net.sf.jsqlparser.expression.RangeExpression;
65+
import net.sf.jsqlparser.expression.TernaryExpression;
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import net.sf.jsqlparser.expression.RowConstructor;
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import net.sf.jsqlparser.expression.RowGetExpression;
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import net.sf.jsqlparser.expression.SignedExpression;
@@ -818,6 +819,16 @@ public <S> StringBuilder visit(RangeExpression rangeExpression, S context) {
818819
return builder;
819820
}
820821

822+
@Override
823+
public <S> StringBuilder visit(TernaryExpression ternaryExpression, S context) {
824+
ternaryExpression.getCondition().accept(this, context);
825+
builder.append(" ? ");
826+
ternaryExpression.getThenExpression().accept(this, context);
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builder.append(" : ");
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ternaryExpression.getElseExpression().accept(this, context);
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return builder;
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}
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@Override
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public <S> StringBuilder visit(Column tableColumn, S context) {
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final Table table = tableColumn.getTable();
@@ -1045,6 +1056,10 @@ public void visit(RangeExpression rangeExpression) {
10451056
visit(rangeExpression, null);
10461057
}
10471058

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public void visit(TernaryExpression ternaryExpression) {
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visit(ternaryExpression, null);
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}
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public void visit(Column tableColumn) {
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visit(tableColumn, null);
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}

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

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@@ -56,6 +56,7 @@
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import net.sf.jsqlparser.expression.OverlapsCondition;
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import net.sf.jsqlparser.expression.PostgresNamedFunctionParameter;
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import net.sf.jsqlparser.expression.RangeExpression;
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import net.sf.jsqlparser.expression.TernaryExpression;
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import net.sf.jsqlparser.expression.RowConstructor;
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import net.sf.jsqlparser.expression.RowGetExpression;
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import net.sf.jsqlparser.expression.SignedExpression;
@@ -1153,6 +1154,14 @@ public <S> Void visit(RangeExpression rangeExpression, S context) {
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return null;
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}
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@Override
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public <S> Void visit(TernaryExpression ternaryExpression, S context) {
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ternaryExpression.getCondition().accept(this, context);
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ternaryExpression.getThenExpression().accept(this, context);
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ternaryExpression.getElseExpression().accept(this, context);
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return null;
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}
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@Override
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public <S> Void visit(TSQLLeftJoin tsqlLeftJoin, S context) {
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tsqlLeftJoin.getLeftExpression().accept(this, context);
@@ -1310,6 +1319,10 @@ public void visit(RangeExpression rangeExpression) {
13101319
visit(rangeExpression, null);
13111320
}
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public void visit(TernaryExpression ternaryExpression) {
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visit(ternaryExpression, null);
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}
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public void visit(TSQLLeftJoin tsqlLeftJoin) {
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visit(tsqlLeftJoin, null);
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}

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

Lines changed: 84 additions & 3 deletions
Original file line numberDiff line numberDiff line change
@@ -101,6 +101,10 @@ public class CCJSqlParser extends AbstractJSqlParser<CCJSqlParser> {
101101
return this;
102102
}
103103

104+
// depth of open ClickHouse-style ternary then-branches: a ":" directly after the
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// then-branch closes the ternary and must not be taken as the JSON path operator
106+
private int ternaryThenBranchDepth = 0;
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104108
private void linkAST(ASTNodeAccess access, Node node) {
105109
access.setASTNode(node);
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node.jjtSetValue(access);
@@ -182,6 +186,11 @@ public class CCJSqlParser extends AbstractJSqlParser<CCJSqlParser> {
182186
// comparison operator follows after "(" "+" ")"
183187
return isComparisonOperator(getToken(4));
184188
}
189+
if ("?".equals(token.image) && isTernaryAhead()) {
190+
// ClickHouse ternary `cond ? then : else` — the `?` must not be taken
191+
// as the PostgreSQL JSON operator here, it is consumed by prattExpressionRest
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return false;
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}
185194
return isComparisonOperator(token);
186195
} catch (Exception e) {
187196
return false;
@@ -212,6 +221,52 @@ public class CCJSqlParser extends AbstractJSqlParser<CCJSqlParser> {
212221
}
213222
}
214223

224+
/**
225+
* True when the pending "?" starts a ClickHouse-style ternary conditional
226+
* {@code cond ? then : else} rather than the PostgreSQL JSON operator:
227+
* a standalone ":" closes the then-branch at the same nesting depth before
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* any expression boundary (",", ";", EOF, an unbalanced closing bracket or a
229+
* clause keyword such as FROM/WHERE).
230+
*/
231+
protected boolean isTernaryAhead() {
232+
try {
233+
int depth = 0;
234+
for (int i = 2; ; i++) {
235+
Token t = getToken(i);
236+
if (t == null || t.kind == EOF) {
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return false;
238+
}
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String image = t.image;
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if ("(".equals(image) || "[".equals(image)) {
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depth++;
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} else if (")".equals(image) || "]".equals(image)) {
243+
if (depth == 0) {
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return false;
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}
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depth--;
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} else if (depth == 0) {
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if (":".equals(image)) {
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return true;
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}
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if (",".equals(image) || ";".equals(image)) {
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return false;
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}
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switch (t.kind) {
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case K_SELECT: case K_FROM: case K_WHERE: case K_GROUP:
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case K_HAVING: case K_ORDER: case K_LIMIT: case K_UNION:
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case K_INTERSECT: case K_EXCEPT: case K_MINUS: case K_INTO:
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case K_VALUES: case K_FETCH: case K_OFFSET:
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return false;
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default:
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break;
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}
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}
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}
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} catch (Exception e) {
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return false;
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}
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}
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215270

216271
/**
217272
* Tokens that have dedicated branches in PrimaryExpression AFTER the Function branch.
@@ -328,12 +383,35 @@ public class CCJSqlParser extends AbstractJSqlParser<CCJSqlParser> {
328383
*/
329384
protected Expression prattExpressionRest(Expression left, int minPrec) throws ParseException {
330385
while (!interrupted) {
331-
int op = getToken(1).kind;
386+
Token t = getToken(1);
387+
int op = t.kind;
388+
boolean ternary = "?".equals(t.image) && isTernaryAhead();
332389
int prec;
333390
if (op == K_AND || op == OP_DOUBLEAND) prec = 4;
334391
else if (op == K_XOR || op == K_OR) prec = 2;
392+
else if (ternary) prec = 2;
335393
else break;
336394
if (prec < minPrec) break;
395+
if (ternary) {
396+
// ClickHouse-style ternary conditional: cond ? then : else
397+
// Right-associative: both branches parse at the full expression
398+
// level (prec 2), nested ternaries are absorbed by the else-branch.
399+
jj_consume_token(op, t.image);
400+
Expression thenExpression;
401+
ternaryThenBranchDepth++;
402+
try {
403+
thenExpression = prattExpressionRest(Condition(), 2);
404+
} finally {
405+
ternaryThenBranchDepth--;
406+
}
407+
if (!":".equals(getToken(1).image)) {
408+
throw new ParseException("Expected ':' closing the ternary conditional operator");
409+
}
410+
jj_consume_token(getToken(1).kind, getToken(1).image);
411+
Expression elseExpression = prattExpressionRest(Condition(), 2);
412+
left = new TernaryExpression(left, thenExpression, elseExpression);
413+
continue;
414+
}
337415
jj_consume_token(op, getToken(1).image);
338416
// +1 makes OR/AND/XOR left-associative
339417
Expression right = prattExpressionRest(Condition(), prec + 1);
@@ -920,6 +998,9 @@ public class CCJSqlParser extends AbstractJSqlParser<CCJSqlParser> {
920998
if (t.kind == OPENING_BRACKET && getToken(2).image.equals("+")) {
921999
return isComparisonOperator(getToken(4));
9221000
}
1001+
// ClickHouse ternary `cond ? then : else` — the `?` must not be taken as the
1002+
// PostgreSQL JSON operator, it is consumed by prattExpressionRest instead
1003+
if ("?".equals(t.image) && isTernaryAhead()) return false;
9231004
if (isComparisonOperator(t)) return true;
9241005
switch (t.kind) {
9251006
// Each suffix's start token:
@@ -7980,7 +8061,7 @@ Expression PrimaryExpression() #PrimaryExpression:
79808061

79818062
// Check for JSON operands
79828063
[
7983-
LOOKAHEAD(2) (
8064+
LOOKAHEAD(2, { ternaryThenBranchDepth == 0 || !":".equals(getToken(1).image) }) (
79848065
LOOKAHEAD(2) (
79858066
token="->"
79868067
|
@@ -8310,7 +8391,7 @@ JsonExpression JsonExpression(Expression expr, List<Map.Entry<Expression, String
83108391
}
83118392

83128393
(
8313-
LOOKAHEAD(2) (
8394+
LOOKAHEAD(2, { ternaryThenBranchDepth == 0 || !":".equals(getToken(1).image) }) (
83148395
token="->"
83158396
|
83168397
token=":"

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