fix(schema-compiler): Avoid ambiguous dimension column mappings for ClickHouse queries

packages/cubejs-schema-compiler/src/adapter/ClickHouseQuery.ts

@@ -266,6 +266,17 @@ export class ClickHouseQuery extends BaseQuery {
     return `ALTER TABLE ${tableName} ADD INDEX ${indexName} (${escapedColumns.join(', ')}) TYPE minmax GRANULARITY 1`;
   }
 
+  public dimensionColumns(cubeAlias) {
+    // For the top-level SELECT statement, explicitly set the column alias.
+    // Clickhouse sometimes includes the "q_0" prefix in the column name, and this
+    // leads to errors during the result mapping.
+    if (cubeAlias === 'q_0') {
+      return this.dimensionAliasNames().map(alias => `${cubeAlias && `${cubeAlias}.` || ''}${alias} ${alias}`);
+    } else {
+      return super.dimensionColumns(cubeAlias);
+    }
+  }
+
   public sqlTemplates() {
     const templates = super.sqlTemplates();
     templates.functions.DATETRUNC = 'DATE_TRUNC({{ args_concat }})';

packages/cubejs-schema-compiler/test/integration/clickhouse/complex-joins.test.ts

@@ -0,0 +1,210 @@
+import { prepareJsCompiler } from '../../unit/PrepareCompiler';
+import { ClickHouseDbRunner } from './ClickHouseDbRunner';
+
+describe('ClickHouse complex joins', () => {
+  jest.setTimeout(20 * 1000);
+
+  const dbRunner = new ClickHouseDbRunner();
+
+  afterAll(async () => {
+    await dbRunner.tearDown();
+  });
+
+  const { compiler, joinGraph, cubeEvaluator } = prepareJsCompiler(`
+    cube(\`Acube\`, {
+      sql: \`SELECT * FROM (SELECT 1 as id, 'Category A' as category, 10 as value UNION ALL
+           SELECT 2, 'Category B', 20 UNION ALL
+           SELECT 3, 'Category C', 30) as t\`,
+
+      joins: {
+        Bcube: {
+          relationship: \`one_to_many\`,
+          sql: \`\${Acube}.id = \${Bcube}.id\`
+        },
+        Ccube: {
+          relationship: \`one_to_many\`,
+          sql: \`\${Acube}.id = \${Ccube}.id\`
+        },
+      },
+
+      measures: {
+        AcubeCount: {
+          type: \`count\`,
+        },
+        AcubeTotalValue: {
+          type: \`sum\`,
+          sql: \`value\`
+        },
+        BcubeTotalValue: {
+          sql: \`\${Bcube.totalValue}\`,
+          type: \`number\`
+        },
+        CcubeTotalAmount: {
+          sql: \`\${Ccube.totalAmount}\`,
+          type: \`number\`
+        },
+      },
+
+      dimensions: {
+        id: {
+          sql: \`id\`,
+          type: \`number\`,
+          primaryKey: true,
+          shown: true,
+          title: \`id\`
+        },
+        category: {
+          sql: \`category\`,
+          type: \`string\`
+        }
+      }
+    });
+
+    cube(\`Bcube\`, {
+      sql: \`SELECT 1 as id, 'Bgroup1' as groupName, 50 as value UNION ALL
+           SELECT 2, 'Bgroup2', 60 UNION ALL
+           SELECT 3, 'Bgroup3', 70\`,
+
+      measures: {
+        count: {
+          type: \`count\`
+        },
+        totalValue: {
+          type: \`sum\`,
+          sql: \`value\`
+        }
+      },
+
+      dimensions: {
+        id: {
+          sql: \`id\`,
+          type: \`number\`,
+          primaryKey: true
+        },
+        groupName: {
+          sql: \`groupName\`,
+          type: \`string\`
+        }
+      }
+    });
+
+    cube(\`Ccube\`, {
+      sql: \`SELECT 1 as id, 'Ctype1' as type, 15 as amount UNION ALL
+           SELECT 2, 'Ctype2', 25 UNION ALL
+           SELECT 3, 'Ctype3', 35\`,
+
+      measures: {
+        count: {
+          type: \`count\`
+        },
+        totalAmount: {
+          type: \`sum\`,
+          sql: \`amount\`
+        }
+      },
+
+      dimensions: {
+        id: {
+          sql: \`id\`,
+          type: \`number\`,
+          primaryKey: true,
+          shown: true
+        },
+        type: {
+          sql: \`type\`,
+          type: \`string\`
+        }
+      }
+    });
+  `);
+
+  it('query with 1 cube join', async () => dbRunner.runQueryTest(
+    {
+      dimensions: [
+        'Acube.category',
+        'Acube.id'
+      ],
+      measures: [
+        'Acube.AcubeCount',
+        'Acube.AcubeTotalValue',
+        'Acube.BcubeTotalValue'
+      ],
+      order: [{
+        id: 'Acube.id',
+        desc: false
+      }],
+      queryType: 'multi'
+    },
+    [
+      {
+        acube__category: 'Category A',
+        acube__id: '1',
+        acube___acube_count: '1',
+        acube___acube_total_value: '10',
+        acube___bcube_total_value: '50',
+      },
+      {
+        acube__category: 'Category B',
+        acube__id: '2',
+        acube___acube_count: '1',
+        acube___acube_total_value: '20',
+        acube___bcube_total_value: '60',
+      },
+      {
+        acube__category: 'Category C',
+        acube__id: '3',
+        acube___acube_count: '1',
+        acube___acube_total_value: '30',
+        acube___bcube_total_value: '70',
+      }
+    ],
+    { joinGraph, cubeEvaluator, compiler }
+  ));
+
+  it('query with 2 cube joins', async () => dbRunner.runQueryTest(
+    {
+      dimensions: [
+        'Acube.category',
+        'Acube.id'
+      ],
+      measures: [
+        'Acube.AcubeCount',
+        'Acube.AcubeTotalValue',
+        'Acube.BcubeTotalValue',
+        'Acube.CcubeTotalAmount'
+      ],
+      order: [{
+        id: 'Acube.id',
+        desc: false
+      }],
+      queryType: 'multi'
+    },
+    [
+      {
+        acube__category: 'Category A',
+        acube__id: '1',
+        acube___acube_count: '1',
+        acube___acube_total_value: '10',
+        acube___bcube_total_value: '50',
+        acube___ccube_total_amount: '15',
+      },
+      {
+        acube__category: 'Category B',
+        acube__id: '2',
+        acube___acube_count: '1',
+        acube___acube_total_value: '20',
+        acube___bcube_total_value: '60',
+        acube___ccube_total_amount: '25',
+      },
+      {
+        acube__category: 'Category C',
+        acube__id: '3',
+        acube___acube_count: '1',
+        acube___acube_total_value: '30',
+        acube___bcube_total_value: '70',
+        acube___ccube_total_amount: '35',
+      }
+    ],
+    { joinGraph, cubeEvaluator, compiler }
+  ));
+});