DbDdlSyntax.java

package com.avaje.ebean.config.dbplatform;

/**
 * Used to support DB specific syntax for DDL generation.
 */
public class DbDdlSyntax {

  private boolean renderIndexForFkey = true;

  private boolean inlinePrimaryKeyConstraint = false;

  private boolean addOneToOneUniqueContraint = false;

  private int maxConstraintNameLength = 32;

  private int columnNameWidth = 25;

  private String dropTableCascade;
  private String dropIfExists;

  private String newLine = "\r\n";

  private String identity = "auto_increment";

  private String pkPrefix = "pk_";

  private String disableReferentialIntegrity;
  private String enableReferentialIntegrity;

  private String foreignKeySuffix;

  /**
   * Return the primary key name for a given bean descriptor.
   */
  public String getPrimaryKeyName(String tableName) {

    String pk = pkPrefix + tableName;
    if (pk.length() > maxConstraintNameLength) {
      // need to trim the primary key name
      pk = pk.substring(0, maxConstraintNameLength);
    }
    return pk;
  }

  /**
   * Return the identity clause for DB's that have identities.
   */
  public String getIdentity() {
    return identity;
  }

  /**
   * Set the identity clause.
   */
  public void setIdentity(String identity) {
    this.identity = identity;
  }

  /**
   * Return the width for padding whitespace after column names.
   */
  public int getColumnNameWidth() {
    return columnNameWidth;
  }

  /**
   * Set the amount of padding to write after the column name.
   */
  public void setColumnNameWidth(int columnNameWidth) {
    this.columnNameWidth = columnNameWidth;
  }

  /**
   * Return the new line character.
   */
  public String getNewLine() {
    return newLine;
  }

  /**
   * Set the new line character.
   */
  public void setNewLine(String newLine) {
    this.newLine = newLine;
  }

  /**
   * Return the prefix used in naming primary keys.
   */
  public String getPkPrefix() {
    return pkPrefix;
  }

  /**
   * Set the prefix used in naming primary keys.
   */
  public void setPkPrefix(String pkPrefix) {
    this.pkPrefix = pkPrefix;
  }

  /**
   * Return the DB specific command to disable referential integrity
   */
  public String getDisableReferentialIntegrity() {
    return disableReferentialIntegrity;
  }

  /**
   * Set the DB specific command to disable referential integrity
   */
  public void setDisableReferentialIntegrity(String disableReferentialIntegrity) {
    this.disableReferentialIntegrity = disableReferentialIntegrity;
  }

  /**
   * Return the DB specific command to enable referential integrity
   */
  public String getEnableReferentialIntegrity() {
    return enableReferentialIntegrity;
  }

  /**
   * Set the DB specific command to enable referential integrity
   */
  public void setEnableReferentialIntegrity(String enableReferentialIntegrity) {
    this.enableReferentialIntegrity = enableReferentialIntegrity;
  }

  /**
   * Return true if indexes should be created for the foreign keys.
   */
  public boolean isRenderIndexForFkey() {
    return renderIndexForFkey;
  }

  /**
   * Set whether indexes should be created for the foreign keys.
   */
  public void setRenderIndexForFkey(boolean renderIndexForFkey) {
    this.renderIndexForFkey = renderIndexForFkey;
  }

  /**
   * Typically returns IF EXISTS (if that is supported by the database platform)
   * or null.
   */
  public String getDropIfExists() {
    return dropIfExists;
  }

  /**
   * Set the IF EXISTS clause for dropping tables if that is supported by the
   * database platform.
   */
  public void setDropIfExists(String dropIfExists) {
    this.dropIfExists = dropIfExists;
  }

  /**
   * Return the cascade option for the drop table command.
   */
  public String getDropTableCascade() {
    return dropTableCascade;
  }

  /**
   * Set the cascade option for the drop table command.
   */
  public void setDropTableCascade(String dropTableCascade) {
    this.dropTableCascade = dropTableCascade;
  }

  /**
   * Return the foreign key suffix.
   */
  public String getForeignKeySuffix() {
    return foreignKeySuffix;
  }

  /**
   * Set the foreign key suffix.
   */
  public void setForeignKeySuffix(String foreignKeySuffix) {
    this.foreignKeySuffix = foreignKeySuffix;
  }

  /**
   * Return the maximum length that constraint names can be for this database.
   */
  public int getMaxConstraintNameLength() {
    return maxConstraintNameLength;
  }

  /**
   * Set the maximum length that constraint names can be for this database.
   */
  public void setMaxConstraintNameLength(int maxFkeyLength) {
    this.maxConstraintNameLength = maxFkeyLength;
  }

  /**
   * Return true if imported side of OneToOne's should have unique constraints
   * generated.
   */
  public boolean isAddOneToOneUniqueContraint() {
    return addOneToOneUniqueContraint;
  }

  /**
   * Set to false for DB's that don't want both a unique and index on the
   * imported OneToOne.
   */
  public void setAddOneToOneUniqueContraint(boolean addOneToOneUniqueContraint) {
    this.addOneToOneUniqueContraint = addOneToOneUniqueContraint;
  }

  /**
   * Return true if primary key constraints should be inlined when they are a
   * single column.
   */
  public boolean isInlinePrimaryKeyConstraint() {
    return inlinePrimaryKeyConstraint;
  }

  /**
   * Set whether to inline primary key constraints.
   */
  public void setInlinePrimaryKeyConstraint(boolean inlinePrimaryKeyConstraint) {
    this.inlinePrimaryKeyConstraint = inlinePrimaryKeyConstraint;
  }

  public String getIndexName(String table, String propName, int ixCount) {

    StringBuilder buffer = new StringBuilder();
    buffer.append("ix_");
    buffer.append(table);
    buffer.append("_");
    buffer.append(propName);

    addSuffix(buffer, ixCount);

    return buffer.toString();
  }

  public String getForeignKeyName(String table, String propName, int fkCount) {

    StringBuilder buffer = new StringBuilder();
    buffer.append("fk_");
    buffer.append(table);
    buffer.append("_");
    buffer.append(propName);

    addSuffix(buffer, fkCount);

    return buffer.toString();
  }

  /**
   * Adds the suffix.
   * 
   * @param buffer
   *          the buffer
   * @param count
   *          the count
   */
  protected void addSuffix(StringBuilder buffer, int count) {
    final String suffixNr = Integer.toString(count);
    final int suffixLen = suffixNr.length() + 1;

    if (buffer.length() + suffixLen > maxConstraintNameLength) {
      buffer.setLength(maxConstraintNameLength - suffixLen);
    }
    buffer.append("_");
    buffer.append(suffixNr);
  }

}