Android Open Source - SimpleStorage S Q L Schema

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Back to project page SimpleStorage.

License

The source code is released under:

Apache License

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Java Source Code

package com.njzk2.simplestorage;
/*from  w ww. jav  a  2s .  c om*/
import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.Map;
import java.util.Map.Entry;

import com.njzk2.simplestorage.handler.TypeHandler;

public class SQLSchema {
  private Map<String, TypeHandler<?>> fields = new HashMap<String, TypeHandler<?>>();

  private Class<? extends Storable> clazz;

  public SQLSchema(Class<? extends Storable> clazz) {
    this.clazz = clazz;
    Field[] clazzFields = SQLHelper.getFields(clazz);
    for (Field field : clazzFields) {
      addField(field.getName(), TypeHandler.getHandler(field));
    }
  }

  private void addField(String fieldName, TypeHandler<?> fieldHandler) {
    fields.put(fieldName, fieldHandler);
  }

  public String toString() {
    StringBuilder builder = new StringBuilder("create table if not exists ");
    builder.append(SQLHelper.getTableName(clazz));
    builder.append(" (_id integer primary key autoincrement");
    for (Entry<String, TypeHandler<?>> field : fields.entrySet()) {
      builder.append(',').append(field.getKey());
      builder.append(' ').append(field.getValue().getSQLType());
    }
    builder.append(");");
    return builder.toString();
  }

  public Collection<String> toAlterStrings(Collection<String> columns) {
    Collection<String> alterStrings = new ArrayList<String>();
    for (Entry<String, TypeHandler<?>> field : fields.entrySet()) {
      if (columns.contains(field.getKey())) {
        // It is not possible to alter an existing column
        continue;
      }
      StringBuilder stringBuilder = new StringBuilder();
      stringBuilder.append("alter table ").append(SQLHelper.getTableName(clazz)).append(" add column ");
      stringBuilder.append(field.getKey()).append(' ').append(field.getValue().getSQLType());
      alterStrings.add(stringBuilder.toString());
    }
    return alterStrings;
  }
}

Java Source Code List