build.c

sqlite数据库管理系统开放源码

      sqliteVdbeChangeP3(v, base+1, pTable->zName, 0);
    }

    if( pTable->iDb==0 ){
      sqliteChangeCookie(db, v);
    }
    sqliteVdbeAddOp(v, OP_Close, 0, 0);
    if( !isView ){
      sqliteVdbeAddOp(v, OP_Destroy, pTable->tnum, pTable->iDb);
      for(pIdx=pTable->pIndex; pIdx; pIdx=pIdx->pNext){
        sqliteVdbeAddOp(v, OP_Destroy, pIdx->tnum, pIdx->iDb);
      }
    }
    sqliteEndWriteOperation(pParse);
  }

  /* Delete the in-memory description of the table.
  **
  ** Exception: if the SQL statement began with the EXPLAIN keyword,
  ** then no changes should be made.
  */
  if( !pParse->explain ){
    sqliteUnlinkAndDeleteTable(db, pTable);
    db->flags |= SQLITE_InternChanges;
  }
  sqliteViewResetAll(db, iDb);
}

/*
** This routine constructs a P3 string suitable for an OP_MakeIdxKey
** opcode and adds that P3 string to the most recently inserted instruction
** in the virtual machine.  The P3 string consists of a single character
** for each column in the index pIdx of table pTab.  If the column uses
** a numeric sort order, then the P3 string character corresponding to
** that column is 'n'.  If the column uses a text sort order, then the
** P3 string is 't'.  See the OP_MakeIdxKey opcode documentation for
** additional information.  See also the sqliteAddKeyType() routine.
*/
void sqliteAddIdxKeyType(Vdbe *v, Index *pIdx){
  char *zType;
  Table *pTab;
  int i, n;
  assert( pIdx!=0 && pIdx->pTable!=0 );
  pTab = pIdx->pTable;
  n = pIdx->nColumn;
  zType = sqliteMallocRaw( n+1 );
  if( zType==0 ) return;
  for(i=0; i<n; i++){
    int iCol = pIdx->aiColumn[i];
    assert( iCol>=0 && iCol<pTab->nCol );
    if( (pTab->aCol[iCol].sortOrder & SQLITE_SO_TYPEMASK)==SQLITE_SO_TEXT ){
      zType[i] = 't';
    }else{
      zType[i] = 'n';
    }
  }
  zType[n] = 0;
  sqliteVdbeChangeP3(v, -1, zType, n);
  sqliteFree(zType);
}

/*
** This routine is called to create a new foreign key on the table
** currently under construction.  pFromCol determines which columns
** in the current table point to the foreign key.  If pFromCol==0 then
** connect the key to the last column inserted.  pTo is the name of
** the table referred to.  pToCol is a list of tables in the other
** pTo table that the foreign key points to.  flags contains all
** information about the conflict resolution algorithms specified
** in the ON DELETE, ON UPDATE and ON INSERT clauses.
**
** An FKey structure is created and added to the table currently
** under construction in the pParse->pNewTable field.  The new FKey
** is not linked into db->aFKey at this point - that does not happen
** until sqliteEndTable().
**
** The foreign key is set for IMMEDIATE processing.  A subsequent call
** to sqliteDeferForeignKey() might change this to DEFERRED.
*/
void sqliteCreateForeignKey(
  Parse *pParse,       /* Parsing context */
  IdList *pFromCol,    /* Columns in this table that point to other table */
  Token *pTo,          /* Name of the other table */
  IdList *pToCol,      /* Columns in the other table */
  int flags            /* Conflict resolution algorithms. */
){
  Table *p = pParse->pNewTable;
  int nByte;
  int i;
  int nCol;
  char *z;
  FKey *pFKey = 0;

  assert( pTo!=0 );
  if( p==0 || pParse->nErr ) goto fk_end;
  if( pFromCol==0 ){
    int iCol = p->nCol-1;
    if( iCol<0 ) goto fk_end;
    if( pToCol && pToCol->nId!=1 ){
      sqliteErrorMsg(pParse, "foreign key on %s"
         " should reference only one column of table %T",
         p->aCol[iCol].zName, pTo);
      goto fk_end;
    }
    nCol = 1;
  }else if( pToCol && pToCol->nId!=pFromCol->nId ){
    sqliteErrorMsg(pParse,
        "number of columns in foreign key does not match the number of "
        "columns in the referenced table");
    goto fk_end;
  }else{
    nCol = pFromCol->nId;
  }
  nByte = sizeof(*pFKey) + nCol*sizeof(pFKey->aCol[0]) + pTo->n + 1;
  if( pToCol ){
    for(i=0; i<pToCol->nId; i++){
      nByte += strlen(pToCol->a[i].zName) + 1;
    }
  }
  pFKey = sqliteMalloc( nByte );
  if( pFKey==0 ) goto fk_end;
  pFKey->pFrom = p;
  pFKey->pNextFrom = p->pFKey;
  z = (char*)&pFKey[1];
  pFKey->aCol = (struct sColMap*)z;
  z += sizeof(struct sColMap)*nCol;
  pFKey->zTo = z;
  memcpy(z, pTo->z, pTo->n);
  z[pTo->n] = 0;
  z += pTo->n+1;
  pFKey->pNextTo = 0;
  pFKey->nCol = nCol;
  if( pFromCol==0 ){
    pFKey->aCol[0].iFrom = p->nCol-1;
  }else{
    for(i=0; i<nCol; i++){
      int j;
      for(j=0; j<p->nCol; j++){
        if( sqliteStrICmp(p->aCol[j].zName, pFromCol->a[i].zName)==0 ){
          pFKey->aCol[i].iFrom = j;
          break;
        }
      }
      if( j>=p->nCol ){
        sqliteErrorMsg(pParse, 
          "unknown column \"%s\" in foreign key definition", 
          pFromCol->a[i].zName);
        goto fk_end;
      }
    }
  }
  if( pToCol ){
    for(i=0; i<nCol; i++){
      int n = strlen(pToCol->a[i].zName);
      pFKey->aCol[i].zCol = z;
      memcpy(z, pToCol->a[i].zName, n);
      z[n] = 0;
      z += n+1;
    }
  }
  pFKey->isDeferred = 0;
  pFKey->deleteConf = flags & 0xff;
  pFKey->updateConf = (flags >> 8 ) & 0xff;
  pFKey->insertConf = (flags >> 16 ) & 0xff;

  /* Link the foreign key to the table as the last step.
  */
  p->pFKey = pFKey;
  pFKey = 0;

fk_end:
  sqliteFree(pFKey);
  sqliteIdListDelete(pFromCol);
  sqliteIdListDelete(pToCol);
}

/*
** This routine is called when an INITIALLY IMMEDIATE or INITIALLY DEFERRED
** clause is seen as part of a foreign key definition.  The isDeferred
** parameter is 1 for INITIALLY DEFERRED and 0 for INITIALLY IMMEDIATE.
** The behavior of the most recently created foreign key is adjusted
** accordingly.
*/
void sqliteDeferForeignKey(Parse *pParse, int isDeferred){
  Table *pTab;
  FKey *pFKey;
  if( (pTab = pParse->pNewTable)==0 || (pFKey = pTab->pFKey)==0 ) return;
  pFKey->isDeferred = isDeferred;
}

/*
** Create a new index for an SQL table.  pIndex is the name of the index 
** and pTable is the name of the table that is to be indexed.  Both will 
** be NULL for a primary key or an index that is created to satisfy a
** UNIQUE constraint.  If pTable and pIndex are NULL, use pParse->pNewTable
** as the table to be indexed.  pParse->pNewTable is a table that is
** currently being constructed by a CREATE TABLE statement.
**
** pList is a list of columns to be indexed.  pList will be NULL if this
** is a primary key or unique-constraint on the most recent column added
** to the table currently under construction.  
*/
void sqliteCreateIndex(
  Parse *pParse,   /* All information about this parse */
  Token *pName,    /* Name of the index.  May be NULL */
  SrcList *pTable, /* Name of the table to index.  Use pParse->pNewTable if 0 */
  IdList *pList,   /* A list of columns to be indexed */
  int onError,     /* OE_Abort, OE_Ignore, OE_Replace, or OE_None */
  Token *pStart,   /* The CREATE token that begins a CREATE TABLE statement */
  Token *pEnd      /* The ")" that closes the CREATE INDEX statement */
){
  Table *pTab;     /* Table to be indexed */
  Index *pIndex;   /* The index to be created */
  char *zName = 0;
  int i, j;
  Token nullId;    /* Fake token for an empty ID list */
  DbFixer sFix;    /* For assigning database names to pTable */
  int isTemp;      /* True for a temporary index */
  sqlite *db = pParse->db;

  if( pParse->nErr || sqlite_malloc_failed ) goto exit_create_index;
  if( db->init.busy 
     && sqliteFixInit(&sFix, pParse, db->init.iDb, "index", pName)
     && sqliteFixSrcList(&sFix, pTable)
  ){
    goto exit_create_index;
  }

  /*
  ** Find the table that is to be indexed.  Return early if not found.
  */
  if( pTable!=0 ){
    assert( pName!=0 );
    assert( pTable->nSrc==1 );
    pTab =  sqliteSrcListLookup(pParse, pTable);
  }else{
    assert( pName==0 );
    pTab =  pParse->pNewTable;
  }
  if( pTab==0 || pParse->nErr ) goto exit_create_index;
  if( pTab->readOnly ){
    sqliteErrorMsg(pParse, "table %s may not be indexed", pTab->zName);
    goto exit_create_index;
  }
  if( pTab->iDb>=2 && db->init.busy==0 ){
    sqliteErrorMsg(pParse, "table %s may not have indices added", pTab->zName);
    goto exit_create_index;
  }
  if( pTab->pSelect ){
    sqliteErrorMsg(pParse, "views may not be indexed");
    goto exit_create_index;
  }
  isTemp = pTab->iDb==1;

  /*
  ** Find the name of the index.  Make sure there is not already another
  ** index or table with the same name.  
  **
  ** Exception:  If we are reading the names of permanent indices from the
  ** sqlite_master table (because some other process changed the schema) and
  ** one of the index names collides with the name of a temporary table or
  ** index, then we will continue to process this index.
  **
  ** If pName==0 it means that we are
  ** dealing with a primary key or UNIQUE constraint.  We have to invent our
  ** own name.
  */
  if( pName && !db->init.busy ){
    Index *pISameName;    /* Another index with the same name */
    Table *pTSameName;    /* A table with same name as the index */
    zName = sqliteTableNameFromToken(pName);
    if( zName==0 ) goto exit_create_index;
    if( (pISameName = sqliteFindIndex(db, zName, 0))!=0 ){
      sqliteErrorMsg(pParse, "index %s already exists", zName);
      goto exit_create_index;
    }
    if( (pTSameName = sqliteFindTable(db, zName, 0))!=0 ){
      sqliteErrorMsg(pParse, "there is already a table named %s", zName);
      goto exit_create_index;
    }
  }else if( pName==0 ){
    char zBuf[30];
    int n;
    Index *pLoop;
    for(pLoop=pTab->pIndex, n=1; pLoop; pLoop=pLoop->pNext, n++){}
    sprintf(zBuf,"%d)",n);
    zName = 0;
    sqliteSetString(&zName, "(", pTab->zName, " autoindex ", zBuf, (char*)0);
    if( zName==0 ) goto exit_create_index;
  }else{
    zName = sqliteTableNameFromToken(pName);
  }

  /* Check for authorization to create an index.
  */
#ifndef SQLITE_OMIT_AUTHORIZATION
  {
    const char *zDb = db->aDb[pTab->iDb].zName;

    assert( pTab->iDb==db->init.iDb || isTemp );
    if( sqliteAuthCheck(pParse, SQLITE_INSERT, SCHEMA_TABLE(isTemp), 0, zDb) ){
      goto exit_create_index;
    }
    i = SQLITE_CREATE_INDEX;
    if( isTemp ) i = SQLITE_CREATE_TEMP_INDEX;
    if( sqliteAuthCheck(pParse, i, zName, pTab->zName, zDb) ){
      goto exit_create_index;
    }
  }
#endif

  /* If pList==0, it means this routine was called to make a primary
  ** key out of the last column added to the table under construction.
  ** So create a fake list to simulate this.
  */
  if( pList==0 ){
    nullId.z = pTab->aCol[pTab->nCol-1].zName;
    nullId.n = strlen(nullId.z);
    pList = sqliteIdListAppend(0, &nullId);
    if( pList==0 ) goto exit_create_index;
  }

  /* 
  ** Allocate the index structure. 
  */
  pIndex = sqliteMalloc( sizeof(Index) + strlen(zName) + 1 +
                        sizeof(int)*pList->nId );
  if( pIndex==0 ) goto exit_create_index;
  pIndex->aiColumn = (int*)&pIndex[1];
  pIndex->zName = (char*)&pIndex->aiColumn[pList->nId];
  strcpy(pIndex->zName, zName);
  pIndex->pTable = pTab;
  pIndex->nColumn = pList->nId;
  pIndex->onError = onError;
  pIndex->autoIndex = pName==0;
  pIndex->iDb = isTemp ? 1 : db->init.iDb;

  /* Scan the names of the columns of the table to be indexed and
  ** load the column indices into the Index structure.  Report an error
  ** if any column is not found.
  */
  for(i=0; i<pList->nId; i++){
    for(j=0; j<pTab->nCol; j++){
      if( sqliteStrICmp(pList->a[i].zName, pTab->aCol[j].zName)==0 ) break;
    }
    if( j>=pTab->nCol ){
      sqliteErrorMsg(pParse, "table %s has no column named %s",
        pTab->zName, pList->a[i].zName);
      sqliteFree(pIndex);
      goto exit_create_index;
    }
    pIndex->aiColumn[i] = j;
  }

  /* Link the new Index structure to its table and to the other
  ** in-memory database structures. 
  */
  if( !pParse->explain ){
    Index *p;
    p = sqliteHashInsert(&db->aDb[pIndex->iDb].idxHash, 
                         pIndex->zName, strlen(pIndex->zName)+1, pIndex);
    if( p ){
      assert( p==pIndex );  /* Malloc must have failed */
      sqliteFree(pIndex);
      goto exit_create_index;
    }
    db->flags |= SQLITE_InternChanges;
  }

  /* When adding an index to the list of indices for a table, make
  ** sure all indices labeled OE_Replace come after all those labeled
  ** OE_Ignore.  This is necessary for the correct operation of UPDATE
  ** and INSERT.
  */
  if( onError!=OE_Replace || pTab->pIndex==0
       || pTab->pIndex->onError==OE_Replace){
    pIndex->pNext = pTab->pIndex;
    pTab->pIndex = pIndex;
  }else{
    Index *pOther = pTab->pIndex;
    while( pOther->pNext && pOther->pNext->onError!=OE_Replace ){
      pOther = pOther->pNext;
    }
    pIndex->pNext = pOther->pNext;
    pOther->pNext = pIndex;
  }

  /* If the db->init.busy is 1 it means we are reading the SQL off the
  ** "sqlite_master" table on the disk.  So do not write to the disk
  ** again.  Extract the table number from the db->init.newTnum field.
  */
  if( db->init.busy && pTable!=0 ){
    pIndex->tnum = db->init.newTnum;
  }

  /* If the db->init.busy is 0 then create the index on disk.  This
  ** involves writing the index into the master table and filling in the
  ** index with the current table contents.
  **
  ** The db->init.busy is 0 when the user first enters a CREATE INDEX 
  ** command.  db->init.busy is 1 when a database is opened and 
  ** CREATE INDEX statements are read out of the master table.  In
  ** the latter case the index already exists on disk, which is why
  ** we don't want to recreate it.
  **
  ** If pTable==0 it means this index is generated as a primary key
  ** or UNIQUE constraint of a CREATE TABLE statement.  Since the table
  ** has just been created, it contains no data and the index initialization
  ** step can be skipped.
  */
  else if( db->init.busy==0 ){
    int n;
    Vdbe *v;
    int lbl1, lbl2;
    int i;
    int addr;

    v = sqliteGetVdbe(pParse);
    if( v==0 ) goto exit_create_index;
    if( pTable!=0 ){
      sqliteBeginWriteOperation(pParse, 0, isTemp);
      sqliteOpenMasterTable(v, isTemp);
    }