SQLiteColumnInfo.java

package net.zer0bandwidth.android.lib.database;

import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * Contains information returned by the {@code table_info} pragma in SQLite.
 * @since zer0bandwidth-net/android 0.1.4 (#26)
 */
public class SQLiteColumnInfo
{
/**
 * Gathers information about the columns in the specified table, and returns
 * the column descriptions in a list.
 * @param db the database to be analyzed
 * @param sTableName the name of the table to be analyzed
 * @return a list of objects describing the columns of the table
 * @see SQLitePortal#getColumnListForTable
 */
public static List<SQLiteColumnInfo> gatherColumnList(
SQLiteDatabase db, String sTableName )
{
Cursor crs = null ;
List<SQLiteColumnInfo> aInfo = new ArrayList<>() ;
try
{
crs = db.rawQuery(
String.format( "PRAGMA main.table_info('%s')", sTableName ),
null ) ;
if( crs.moveToFirst() )
{
do
{
SQLiteColumnInfo info = new SQLiteColumnInfo() ;
info.sTableName = sTableName ;
info.nColumnID = crs.getInt(0) ;
info.sColumnName = crs.getString(1) ;
info.sColumnType = crs.getString(2) ;
info.bNotNull = SQLitePortal.intToBool( crs.getInt(3) ) ;
info.sDefault = crs.getString(4) ;
info.bPrimaryKey = SQLitePortal.intToBool( crs.getInt(5) ) ;
aInfo.add(info) ;
} while( crs.moveToNext() ) ;
}
}
finally
{ SQLitePortal.closeCursor(crs) ; }

return aInfo ;
}

/**
 * Gathers information about the columns in the specified table, and returns
 * the column descriptions in a map.
 * @param db the database to be analyzed
 * @param sTableName the name of the table to be analyzed
 * @return a map of column names to objects describing those columns
 * @see SQLitePortal#getColumnMapForTable
 */
public static Map<String,SQLiteColumnInfo> gatherColumnMap(
SQLiteDatabase db, String sTableName )
{
List<SQLiteColumnInfo> aInfo = gatherColumnList( db, sTableName ) ;
Map<String,SQLiteColumnInfo> mapInfo = new HashMap<>() ;
for( SQLiteColumnInfo info : aInfo )
mapInfo.put( info.sColumnName, info ) ;
return mapInfo ;
}

/** The name of the table containing this column. */
public String sTableName = null ;

/** The numeric ID of the column in any given row. */
public int nColumnID = -1 ;

/** The name of the column in the table definition. */
public String sColumnName = null ;

/** The magic SQLite token indicating this column's data type. */
public String sColumnType = null ;

/** Indicates whether the column is defined {@code NOT NULL}. */
public boolean bNotNull = false ;

/** The default value of the column, as a string. */
public String sDefault = null ;

/** Indicates whether the column is the table's primary key. */
public boolean bPrimaryKey = false ;
}