From 225d3437e073b388623d26c31f9bd59076917583 Mon Sep 17 00:00:00 2001
From: Martin Kleusberg <mkleusberg@gmail.com>
Date: Thu, 18 Aug 2016 20:33:39 +0200
Subject: [PATCH] Add parsing support for UNIQUE table constraints

See issue #540.
---
 src/sqlitetypes.cpp | 53 +++++++++++++++++++++++++++++++++++----------
 src/sqlitetypes.h   |  7 +++++-
 2 files changed, 47 insertions(+), 13 deletions(-)

diff --git a/src/sqlitetypes.cpp b/src/sqlitetypes.cpp
index 1aed29e7..7431d6ac 100644
--- a/src/sqlitetypes.cpp
+++ b/src/sqlitetypes.cpp
@@ -127,6 +127,27 @@ void Table::setFields(const FieldVector &fields)
     m_fields = fields;
 }
 
+void Table::setField(int index, FieldPtr f)
+{
+    FieldPtr oldField = m_fields[index];
+    m_fields[index] = f;
+
+    // Update unique constraints. If an existing field is updated but was used in a unique constraint, the pointer in the
+    // unique constraint needs to be updated to the new field, too.
+    if(oldField)
+    {
+        for(int i=0;i<m_uniqueConstraints.size();++i)
+        {
+            FieldVector& constraint = m_uniqueConstraints[i];
+            for(int j=0;j<constraint.size();++j)
+            {
+                if(constraint[i] == oldField)
+                    constraint[i] = f;
+            }
+        }
+    }
+}
+
 int Table::findField(const QString &sname)
 {
     for(int i = 0; i < m_fields.count(); ++i)
@@ -231,6 +252,15 @@ QString Table::sql() const
             sql += pk + ")";
     }
 
+    // unique constraints
+    foreach(FieldVector constraint, m_uniqueConstraints)
+    {
+        QStringList fieldnames;
+        foreach(FieldPtr field, constraint)
+            fieldnames.append(escapeIdentifier(field->name()));
+        sql += QString(",\n\tUNIQUE(%1)").arg(fieldnames.join(","));
+    }
+
     // foreign keys
     foreach(FieldPtr f, m_fields)
     {
@@ -247,6 +277,11 @@ QString Table::sql() const
     return sql + ";";
 }
 
+void Table::addUniqueConstraint(FieldVector fields)
+{
+    m_uniqueConstraints.push_back(fields);
+}
+
 namespace
 {
 QString identifier(antlr::RefAST ident)
@@ -386,13 +421,12 @@ Table CreateTableWalker::table()
                 {
                     tc = tc->getNextSibling(); // skip UNIQUE
                     tc = tc->getNextSibling(); // skip LPAREN
-                    QVector<int> uniquefieldsindex;
+                    FieldVector fields;
                     do
                     {
                         QString col = columnname(tc);
-                        int fieldindex = tab.findField(col);
-                        if(fieldindex != -1)
-                            uniquefieldsindex.append(fieldindex);
+                        FieldPtr field = tab.field(tab.findField(col));
+                        fields.push_back(field);
 
                         tc = tc->getNextSibling();
                         if(tc != antlr::nullAST
@@ -410,15 +444,10 @@ Table CreateTableWalker::table()
                         }
                     } while(tc != antlr::nullAST && tc->getType() != sqlite3TokenTypes::RPAREN);
 
-                    if(uniquefieldsindex.size() == 1)
-                    {
-                        tab.fields().at(uniquefieldsindex[0])->setUnique(true);
-                    }
+                    if(fields.size() == 1)
+                        fields[0]->setUnique(true);
                     else
-                    {
-                        // else save on table a unique with more than one field
-                        m_bModifySupported = false;
-                    }
+                        tab.addUniqueConstraint(fields);
                 }
                 break;
                 case sqlite3TokenTypes::FOREIGN:
diff --git a/src/sqlitetypes.h b/src/sqlitetypes.h
index c65956da..6b3ffc9e 100644
--- a/src/sqlitetypes.h
+++ b/src/sqlitetypes.h
@@ -106,6 +106,7 @@ private:
 
 typedef QSharedPointer<Field> FieldPtr;
 typedef QVector< FieldPtr > FieldVector;
+
 class Table
 {
 public:
@@ -126,13 +127,16 @@ public:
     void addField(const FieldPtr& f);
     bool removeField(const QString& sFieldName);
     void setFields(const FieldVector& fields);
-    void setField(int index, FieldPtr f) { m_fields[index] = f; }
+    void setField(int index, FieldPtr f);
+    const FieldPtr& field(int index) { return m_fields[index]; }
     QStringList fieldNames() const;
     void setRowidColumn(const QString& rowid) {  m_rowidColumn = rowid; }
     const QString& rowidColumn() const { return m_rowidColumn; }
     bool isWithoutRowidTable() const { return m_rowidColumn != "_rowid_"; }
     void clear();
 
+    void addUniqueConstraint(FieldVector fields);
+
     /**
      * @brief findField Finds a field and returns the index.
      * @param sname
@@ -159,6 +163,7 @@ private:
     QString m_name;
     FieldVector m_fields;
     QString m_rowidColumn;
+    QVector<FieldVector> m_uniqueConstraints;
 };
 
 /**